fix(install): stop libblockdev matching the desktop-environment check

dpkg -l | grep -E '^ii.*kde' searched the description column too, so
unrelated packages (libblockdev-*) set DESKTOP_DETECTED on Raspberry Pi OS
Lite. Match on the installed package name only, anchored.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VZNWFWprcFYGfuf1JAyrBJ

CHANGELOG.md

@@ -19,6 +19,347 @@ accepts both, but the store flags the old spelling as deprecated
 
 ## Unreleased
 
+### Tooling
+
+- `test/test_sports_helpers.py`'s parity tests pass again with
+  `LEDMATRIX_PLUGINS` set. The scoreboards deleted their copies of the
+  `sports_helpers` bodies and constants when they adopted `SportsHelpersMixin`
+  (ledmatrix-plugins #563/#564), and the 19 tests still expected them. A copy
+  that is gone now counts as adopted when the plugin imports
+  `src.common.sports_helpers`, as the stage 3/4 and game-over parity tests
+  already do; a copy that remains must still match.
+
+## 3.8.2
+
+The display hands freed memory back to the OS (#774), and sports consolidation
+family 6: `src.common.sports_favorites`, which the scoreboards adopt by
+flooring on 3.8.2 (#775).
+
+### The display hands freed memory back to the OS
+
+The display process's resident memory climbed in steps for hours while the
+data it held stayed flat: glibc keeps what Python frees in per-thread malloc
+arenas and returns little of it. `src/malloc_tuning.py` (new, standard library
+only, a no-op off Linux/glibc) does two things in-process, so it reaches
+devices without re-running the installer:
+
+- **Arena cap at start-up.** `run.py` calls `mallopt(M_ARENA_MAX, 2)` before any
+  thread exists, the same cap as the unit's `Environment=MALLOC_ARENA_MAX=2`.
+  Units installed before that line never got it (systemd runs the copy in
+  `/etc/systemd/system`); a `MALLOC_ARENA_MAX` in the environment still wins.
+- **`malloc_trim(0)` between screens**, at most every 5 minutes, from the top of
+  the render loop where no frame is being drawn. Measured on a Pi 4: 2-11 ms
+  per call.
+
+On ledpi (Pi 4, 192x48, Vegas on, nine plugins, a unit without
+`MALLOC_ARENA_MAX`), alternated main / branch / branch / main arms of 2.5 h:
+two hours in, resident memory was 551 MB on main (the second main arm was
+already at 651 MB after 1 h 44 min) against 412 and 386 MB with this change,
+and the 20-minute frame soaks came out at 0.147-0.165% late against main's
+0.151-0.188%.
+
+### New modules
+
+- `src/common/sports_favorites.py` -- sports consolidation family 6, once the
+  plugins made `_is_favorite_game` (seven bodies), `_select_games_for_display`
+  (two) and `_select_recent_games_for_display` (three) one each:
+  `SportsFavoritesMixin` (`SportsCore`: `_is_favorite_game`, `_favorite_code`),
+  `SportsUpcomingFavoritesMixin` and `SportsRecentFavoritesMixin` (the
+  favourites-only picks). Each side of a game is named by the 3.5.0
+  `_favorite_key` seam and compared with `favorite_teams` stripped and
+  upper-cased; nrl overrides the key with the ESPN team id. Only a game with an
+  id can be a duplicate. A plugin may inherit the mixins once it floors on
+  3.8.2, and deletes its copies then. (#775)
+
+## 3.8.1
+
+Smooth scrolling at the slower speeds, and the fixes and performance work
+since 3.8.0. Highlights: the default 50 px/s and every other held-frame speed
+now scroll cleanly (below), Raspberry Pi OS Bookworm is supported alongside
+Trixie, updates refresh the systemd units, the display control socket gains
+stages 2 and 3, the shared fetch service lands (stages 1 and 2), and a run of
+web UI and Plugin Manager fixes. One new module is for plugins:
+`src.common.sports_game_over` (sports family 5), which the scoreboards adopt
+by flooring on 3.8.1; the other new modules are core-internal and set no
+`ledmatrix_min_version` floor.
+
+### Scroll speed
+
+These two entries were the reason for this release: on 3.8.0 a slow scroll
+either stepped or showed a half-pixel tear across the middle of the panel,
+so only speeds of one pixel per refresh looked right.
+
+- The Vegas Scroll Speed slider now says what the panel will do with the speed
+  it is on, and offers the nearest smooth ones to click. Only speeds that advance
+  a whole number of pixels per refresh look smooth, and which those are depends
+  on the panel (`GET /api/v3/config/scroll-speed-advice`, built on
+  `scroll_config.speed_advice()`; it uses the refresh the display measured, not
+  the `limit_refresh_rate_hz` cap). The slider steps by 1 px/s instead of 5.
+- The default 50 px/s no longer snaps to a stepped 48 px/s (2 px every 5
+  refreshes, 24 fps) on a 120 Hz panel: `solve_crisp()` now prefers 60 or 40 px/s,
+  which move one pixel at a time. 100 Hz panels are unaffected. (#710)
+- A held-frame scroll (one pixel every two or more refreshes, such as 50 or
+  60 px/s on a 100-120 Hz panel) no longer shows a half-pixel step across the
+  middle of the panel. Scan-order compensation ran only at one frame per
+  refresh; a held frame is now presented as a sequence of swaps
+  (`scan_order.refresh_plan()`), so the half of the panel that scans later
+  steps one refresh after the rest. It is skipped when a blit takes more than
+  half a refresh, since the second blit has to land before the next vsync.
+  (#711)
+
+### Web UI: the Display tab is an ES-module page, with a page-visibility service (stage 4)
+
+- New `static/v3/js/core/visibility.js`: each page module gets
+  `ctx.visibility` with `whileVisible(start, stop)`, `every(ms, fn)` and
+  `isVisible()`. Work registered there runs only while the page's tab is the
+  active tab and the browser tab is visible, and ends when the page is
+  swapped out, with no teardown code in the page. It reads the active tab
+  from `window.LEDVisibility`, so it agrees with the classic partials that
+  still use that directly. The page registry gained a `mountContext` option
+  for services bound to one mounted page.
+- The Display tab's inline scripts are now `static/v3/js/pages/display.js`.
+  The partial has no inline script, `onclick` or `onchange` any more. The
+  multi-display sync status poll (every 5 s) runs through
+  `ctx.visibility.every`; the status and scroll-speed hint requests go
+  through `core/api.js` with the page's abort signal, and so does the Vegas
+  order widget's plugin-list request.
+- Behaviour differences: with sync on, opening the tab asks for the status
+  once instead of twice, and a Display tab loaded while not on screen waits
+  until it is. A login redirect during a poll no longer flashes "Sync status
+  unavailable". The `window.syncStatusInterval` timer id is gone (nothing
+  read it). A pending scroll-hint request or widget retry is dropped when
+  the partial is swapped out.
+- `window.updateSyncUI` keeps working as a deprecated alias through
+  `window.LEDMatrix` (one console warning).
+- New suites `test/js/dom/test_visibility_service.js` and
+  `dom/test_display_page.js`; `unit/test_display_partial_ids.js` imports the
+  module instead of slicing the template.
+
+### Plugins ask for the screen in-process: `request_on_demand()` / `end_on_demand()`
+
+The in-process way in that stage 5 of the control socket needed
+(`docs/IPC_CONTROL_SOCKET.md`, "Plugins in the display process").
+
+- **`BasePlugin.request_on_demand(mode=None, duration=None, pinned=False)`**
+  shows the plugin now, and **`BasePlugin.end_on_demand()`** gives the
+  screen back. Both are safe from any thread (an MQTT callback, a timer
+  thread): `PluginManager.request_on_demand()` / `end_on_demand()` hand the
+  request to `DisplayController.submit_plugin_on_demand()`, which only
+  queues it (at most 32) and wakes the render thread through the control
+  socket's flag (`ControlServer.wake()`). The render thread applies it with
+  the socket's commands, through the same handler as a web on-demand
+  request, so it lands within a frame rather than on the mailbox's
+  once-a-second look. Both return the request id, or `None` when no display
+  runs in the process (the web interface, `scripts/check_plugin.py`) or the
+  queue is full.
+- **A plugin's stop ends only its own session.** A mailbox stop still ends
+  any session, whoever started it.
+- **Older cores.** Plugins detect the methods with `hasattr` and write the
+  `display_on_demand_request` mailbox when they are missing or answer
+  `None`; the pattern is in `docs/PLUGIN_API_REFERENCE.md` ("On-demand
+  display"). The display still reads the mailbox for plugins that write it.
+
+### Web UI: Schedule and General are ES-module pages (stage 3)
+
+- The Schedule and General tabs follow stage 2 (#727): their inline
+  `<script>` blocks are now `static/v3/js/pages/schedule.js` and
+  `pages/general.js`, started once per swap-in by the page registry and
+  stopped on swap-out. Neither partial has an inline script, `onclick`,
+  `onsubmit` or `oninput` any more.
+- Schedule: both pickers are drawn from the saved config the partial
+  carries as JSON in `data-schedule-config` / `data-dim-schedule-config`.
+  The forms' `hx-on` save handlers became one `htmx:afterRequest` listener
+  on the page; the forms are marked `data-reports-result`, which `app.js`
+  now honours like an `hx-on` after-request handler, so a save still shows
+  one notification.
+- General: the timezone picker reads the saved zone from `data-timezone`.
+  The Security section's forms and buttons carry `data-action` and use one
+  delegated submit and one delegated click listener, so a token row added
+  after a create needs no listener of its own. Requests go through
+  `core/api.js`: the optional login's "sign in again" answer no longer
+  flashes an error while the page navigates to the login form. A login
+  change made just before a swap is still reported.
+- Old globals keep working as deprecated aliases through `window.LEDMatrix`
+  (one console warning each): `handleScheduleResponse`,
+  `handleDimScheduleResponse`, and `webLogin` (its five methods).
+- New DOM suites `test/js/dom/test_{schedule,general}_page.js`;
+  `unit/test_general_web_login_token.js` imports the module instead of
+  slicing the template, and `unit/test_restart_banner.js` covers
+  `data-reports-result`.
+
+### The control socket carries every web command; the mailboxes are a fallback
+
+Stage 4 of the web → display control socket (`docs/IPC_CONTROL_SOCKET.md`).
+
+- **Mailbox only when the socket cannot carry it.** The on-demand routes
+  (`POST /api/v3/display/on-demand/start` and `/stop`) write the
+  `display_on_demand_request` mailbox only when the display never had the
+  request: no socket (a stopped display, one older than the socket), a
+  refused or timed-out connect, or a display too old to know the command.
+  A display that had it and refused or did not answer (a full queue, bad
+  arguments, silence after the send) is answered `503` (`400` for bad
+  arguments) with `socket_error`, and no mailbox copy is written: the
+  display may have applied it, or would refuse the copy too. A stop with
+  `stop_service` still stops the service. `src.ipc.client.should_fall_back()`
+  holds the rule; `ControlError.sent` says whether the display had the
+  request.
+- **`errors.clear`.** `POST /api/v3/errors/clear` goes over the socket: the
+  display clears its error records and republishes its error snapshot
+  before it answers, so the response says `applied: true` with the
+  display's own `cleared_count`. The `plugin_error_clear_request` mailbox
+  is written only on the same fallback rule (a display from before this
+  release answers `unknown_command`, and gets the mailbox). A display that
+  had it and failed answers `503`. The error snapshot gains
+  `applied_clear_cutoff`, so an older mailbox request is not shown as
+  pending once a wider clear has been applied.
+- **The display looks at the mailboxes less, and more cheaply.** While the
+  control socket is up, the on-demand mailbox is looked at once a second
+  instead of every 0.25 s (`MAILBOX_POLL_INTERVAL_WITH_SOCKET`), and both
+  mailboxes are read only when their file changed since the last look:
+  otherwise a look is one `stat()` (`CacheManager.file_signature`,
+  `MailboxWatch`). A socket command no longer reads or deletes the mailbox
+  file. A duplicate already processed is taken out of the mailbox, rather
+  than re-read for an hour. Without a socket (Windows,
+  `LEDMATRIX_CONTROL_SOCKET=off`) the mailbox is read every 0.25 s as before.
+- **Kept for one release.** The display still reads both mailboxes, so an
+  older web interface (or a web user not yet in the socket's group) keeps
+  working during an upgrade, and still writes `display_current_state`,
+  `display_on_demand_state` and `plugin_runtime_snapshot` for the readers'
+  fallback. A request that comes through the on-demand mailbox while the
+  socket is up is logged once per writer: plugins that write
+  `display_on_demand_request` themselves (birdnet-go, mqtt-notifications,
+  on-air, pomodoro-timer) now get the screen within a second rather than a
+  quarter second, and need an in-process way in before the mailbox goes.
+
+### Display loop stage 3: a ScreenRunner, and the Arbiter decides every screen
+
+Internal; no behaviour change. Stage 3 of `docs/RUN_LOOP_REDESIGN.md`.
+
+- Each screen runs in `ScreenRunner` (`src/screen_runner.py`): the first
+  frame, the 125 Hz or 1 Hz frame loop, the make-up dwell and the
+  dynamic-duration exit, moved out of `DisplayController.run()` with their
+  pacing unchanged. It paces with an injected clock and returns an
+  `Outcome` whose `ExitReason` is `DURATION`, `CYCLE_COMPLETE`, `EMPTY`,
+  `ERROR`, `DISPLAY_FALSE`, `RELOAD` or `PREEMPTED`. `PREEMPTED` replaces
+  the five "did the mode change under this screen?" re-checks.
+- `Arbiter.decide()` now answers for on-demand, live priority and the
+  rotation too (Sources `ON_DEMAND`, `LIVE`, `ROTATION`); `LEGACY` means
+  only Vegas, whose iteration moves to stage 4. The on-demand session, the
+  rotation's position and the live resume point are snapshotted into
+  `ArbiterState`, whose pure transitions (`next_on_demand`, `claim_live`,
+  `release_live`, `after`) replace the bookkeeping in `_resolve_active_mode`,
+  `_apply_live_priority` and `_advance_after_screen`.
+- Between frames, the runner's service points make one
+  `decide(..., running=plan)` call instead of `_check_live_takeover`,
+  `_screen_preempted` and `_wifi_notice_pending` one after another. The
+  WiFi notice file is still read exactly where it was (the read is
+  throttled and deletes an expired file).
+- A Vegas pass scans the live-priority plugins once instead of twice at the
+  same instant.
+- The golden traces are byte-identical, and a capture of all 67 harness
+  runs in the suite (every sleep, frame, read and scan) matches `main`
+  apart from the duplicate scan above and one moment: in the 125 Hz loop a
+  live takeover's state change is made after the frame's 8 ms sleep rather
+  than before it, ending the screen at the same frame as before.
+- New module: `src/screen_runner.py`. Core-internal: plugins have no reason
+  to import it, so it sets no `ledmatrix_min_version` floor.
+
+### A scrolling screen held by its plugin's update() is reported
+
+- While a plugin's `update()` runs it holds the plugin's lock, and that
+  plugin's frames are skipped: on a scroller, a frozen strip, with nothing
+  logged (and a freeze of 5 s or more is a gap, not a freeze, to the frame
+  stats). The high-FPS loop now times each run of skipped frames; one of
+  250 ms or more logs `Display of <plugin> held N ms by its update()`
+  (rate-limited per plugin) when it ends, and is recorded on the plugin's
+  health as a `display hold` busy skip, which never counts toward the
+  circuit breaker. The 1 Hz loop is left out: its frames are a second apart,
+  so one skipped frame there measures nothing and freezes nothing visible.
+
+### Fixed
+
+- Unloading a plugin now forgets the fonts its manifest registered, not only
+  the fonts it reported using. Its `plugin_id::family` entries kept resolving
+  and their cached font objects stayed alive until a restart, and a family a
+  reinstalled plugin's manifest dropped stayed registered. The new
+  `FontManager.forget_plugin_fonts(plugin_id)` does the cleanup;
+  `PluginManager.unload_plugin()` and a failed load call it alongside
+  `forget_manager_fonts()`, and a reload registers the manifest's fonts again.
+
+- The web preview and `/api/v3/display/current` no longer stay black for a
+  whole screen that draws its card once and then holds it. The snapshot is
+  written from `update_display()` at most once per write interval, so a frame
+  pushed inside that interval was skipped and left for the next
+  `update_display()` -- which such a screen never makes. Soccer's
+  recent/upcoming cards skip redundant redraws, and the first one after an
+  on-demand start lands a few milliseconds after the start's clear wrote a
+  black frame: on ledpi the preview showed 0 lit pixels for the whole 15 s
+  while the panel showed the card. `DisplayManager` now remembers a skipped
+  changed frame, and the render loop writes it (`write_owed_snapshot()`)
+  once the interval has passed. The cadence is unchanged, and nothing extra
+  runs when no frame is owed.
+- The installed-plugins list (`GET /api/v3/plugins/installed`) no longer
+  waits on GitHub. Its comment said the registry lookup made no network call,
+  but on a cold or expired cache `get_registry_info()` downloads plugins.json
+  (10 s timeout, three attempts), and with nothing cached to fall back on
+  every plugin's lookup repeated that: offline, 5 plugins took 11 s with DNS
+  failing and 2 plugins 65 s with the route black-holed, on every load. The
+  list now reads the registry copy already in memory, however old
+  (`get_cached_registry_info()`); with none yet it returns without update or
+  verified badges and starts one background refresh
+  (`refresh_registry_in_background()`, backing off for a minute after an
+  offline failure), so a later load has them. The store, install and update
+  paths still fetch as before.
+- A sports live manager's idle back-off now honours every pending kickoff,
+  not just the first. `_note_scheduled_start_candidate()` kept one kickoff
+  and, while it was inside its 15-minute grace, refused every later one; by
+  the time the grace ended the later one had passed and was refused again.
+  So of two favourites kicking off within 15 minutes of each other, the
+  second lost its own grace: if the first game was not live by then (a rain
+  delay, a postponement, ESPN slow to flip it) and ESPN had not flipped the
+  second either, the back-off went back to its ceiling and the second game
+  was noticed up to the ceiling (15 minutes by default) late. Later
+  kickoffs now wait in a short queue (`_later_scheduled_starts`, the
+  earliest 8) and each takes over with a grace of its own when the one
+  before it expires. A kickoff still
+  holds the live cadence for at most its own grace, so a postponed game
+  costs the same quarter of an hour as before.
+
+### ESPN date-range fetches: fewer requests, fewer at once
+
+A soccer board (8 leagues, ESPN rejecting `dates=` ranges) logged ~90
+`NameResolutionError` lines and an `update() timed out` at every start on a
+Pi: each league's fortnight-either-side window was 29 day requests, fetched
+by several managers at once, ~40 in flight. Measured against live ESPN with
+soccer-scoreboard 2.39.2, alternating runs: **~450 requests per start, peak
+~45 in flight, ~75 DNS lookups -> 46 requests, peak 13, ~30 lookups**.
+
+- `fetch_espn_date_chunks()` asks for a window's partial edge month whole
+  when the window covers `ESPN_MONTH_COVER_MIN_DAYS` (7) or more of its days,
+  and trims the answer to the window's days by each event's US Eastern start
+  date -- the day ESPN's `dates=YYYYMMDD` means (417 of 417 live soccer
+  events matched). A 29-day window spanning two months is 2 requests instead
+  of 29. Short windows (a live poll's 1-2 days) stay day by day. A trimmed
+  month that comes back at the 500-event cap re-asks only the window's days.
+  An event with no readable date is kept. New: `espn_request_chunks()`.
+- Chunk requests share one process-wide cap of `ESPN_CHUNK_WORKERS` (6) in
+  flight, across every window being fetched, instead of six per window.
+- A new process starts as if a range had just been rejected, so it no longer
+  spends one doomed 400 per window at every start (eleven at once from a
+  soccer board); the range is still retried `RANGE_RETRY_SECONDS` in.
+
+### Fetch stats: bytes on the wire, not just decoded
+
+`GET /api/v3/plugins/fetch-stats` reported only `bytes`, the decoded body
+size, and that read as the download volume. ESPN gzips every scoreboard, so
+it overstated what crossed the network about 14x: a college football
+Saturday's scoreboard is 865 KB decoded and 63 KB on the wire, and ledpi's
+"643 MB in 6 hours" of football was ~47 MB of actual traffic. Every counter
+set (totals, per plugin, per host) now has `wire_bytes` too, read from
+urllib3's count of the raw bytes it took off the socket. A response with no
+urllib3 response behind it is counted at its decoded size. `bytes` keeps its
+meaning.
+
 ### Cheap per-frame and per-fetch savings
 
 - `BaseOddsManager.get_odds()` no longer pretty-prints every odds response
@@ -457,6 +798,16 @@ policies are unchanged.
 - `src/display_arbiter.py` -- the display loop's Arbiter (see Tooling).
   Core-internal: plugins have no reason to import it, so it sets no
   `ledmatrix_min_version` floor.
+- `src/common/sports_game_over.py` -- `SportsGameOverMixin`, sports
+  consolidation family 5: `_is_game_really_over`, the scoreboards'
+  `SportsLive` check that drops a game ESPN still lists as live, once the
+  plugins made their five bodies one. Over on a final period text, or on a
+  0:00 clock from period `FINAL_PERIOD` on unless the score is level (a tie
+  at the end of regulation goes to overtime). `FINAL_PERIOD` is the per-sport
+  class attribute, `None` by default (the clock never ends a game); the
+  scoreboards declare 3 (hockey), 4 (basketball, football, lacrosse) or
+  `None`. List the mixin before `SportsLiveSharedMixin`. A plugin may import
+  it once it floors on 3.8.1, and deletes its copy then. (#770)
 
 ### Tooling
 
@@ -505,6 +856,54 @@ policies are unchanged.
   stored `ttl` was stretched the same way. A memory hit is now also checked against
   the record's own timestamp, and a stale one falls through to disk, which
   returns a newer write if there is one.
+- An on-demand request that names a `*_live` mode now shows that mode. On
+  ledpi, `{"plugin_id": "football-scoreboard", "mode": "ncaa_fb_live"}` with
+  15 college games on answered 200 and showed `nfl_recent`. The session's
+  mode list kept a live mode only when the plugin's `has_live_content()`
+  said so. That method answers the live-priority question, and the sports
+  plugins answer it for favourite teams only. A mode the request names
+  (not one resolved from a bare plugin id) now leads the session, with the
+  plugin's other modes after it. If it has nothing to draw, the session
+  moves on to the next of those modes, like any empty on-demand mode. The
+  name is saved with the session (`named_mode` in
+  `display_on_demand_config`), so a restart resumes on it.
+- A restart during an on-demand session whose plugin then fails to load no
+  longer leaves a session with no modes. On ledpi, `clock-simple` failed
+  config validation after a crash. The display logged `No valid display
+  modes found for on-demand plugin 'clock-simple' after restoration` and
+  kept reporting the session as active until its first pass ended it as
+  `idle`. The cached request stayed behind for the next restart. The session
+  now ends at startup with status `error` and error `restore-failed`, which
+  `/display/on-demand/status` reports, and the cached request is dropped. The
+  same applies when the plugin system itself fails to start.
+- `POST /api/v3/config/schedule` and `/config/dim-schedule` accept a
+  disabled per-day schedule with every day off. That is the shape
+  `config.template.json` ships, so posting back what GET returned on a fresh
+  install answered 400 "At least one day must be enabled". An enabled per-day
+  schedule still needs a day on. A day that is off now keeps the times it
+  was posted with (the schedule picker sends them). Before, saving dropped
+  them, so turning the day back on showed the defaults.
+- `POST /api/v3/config/main` answers `restart_required: true` only when the
+  save changed a setting the running display does not apply by itself.
+  Brightness (`brightness.set` and the config watcher), the per-mode
+  durations and plugin sections are applied live. A brightness-only save,
+  such as the MQTT bridge's slider, or a save that changed nothing, no longer
+  shows the restart banner. Hardware, rotation order, timezone and every
+  other setting still ask for the restart.
+- `GET /api/v3/health` reports `degraded` when the display service is
+  stopped. Before, only the sub-checks changed, and the overall status stayed
+  `healthy` for as long as the last preview frame was under 60 s old.
+  `checks.display_loop.status` is now `stopped` when three things agree:
+  systemd says the service is not active, the control socket does not
+  answer, and there is no live heartbeat. Where the platform has no socket
+  (Windows) or it is switched off, nothing changes.
+- `GET /api/v3/display/current-status` no longer reports the stopped
+  display's last state (`is_display_active: true`) from the cache for up to
+  120 s. When the control socket does not answer and the render loop's
+  heartbeat is absent, stale, or from a process that is gone (#726's rules),
+  the answer is unknown, with every field `null`. A display that still beats
+  without a socket, Windows and a socket switched off read the cache as
+  before. New `web_interface.display_state.display_gone()`.
 - The garbage-collection timer (`GcMonitor`, above) no longer prints
   `Exception ignored while calling GC callback ... 'NoneType' object has no
   attribute 'perf_counter'` when the display service or a test run exits.
@@ -885,25 +1284,6 @@ policies are unchanged.
   a runtime publisher that stops still goes `stale`, and a subscription that
   goes quiet still falls back to the cache. The cache path's 120 s rule is
   unchanged.
-- A plugin that pauses the Vegas scroll gets its pause when its display
-  duration is not a plain number. Several plugins (clock-simple, calendar,
-  countdown) return `display_duration` as it is in config.json, so a value
-  saved as `"20"` or `null` (the raw config editor, a hand edit) reached the
-  pause as a string or None; comparing it with the clock raised, and the
-  plugin flashed up and the scroll went straight on, at every one of its
-  turns. `inf` held the pause until something interrupted it, and 0, a
-  negative number or NaN ended it at once. The pause now reads the duration
-  as the rotation does (`finite_seconds()` in `base_plugin`): a numeric
-  string counts, anything else that is not a finite number (or a
-  `get_display_duration()` that raises) pauses for 30 s, and a number at or
-  below zero for 15 s, with one warning per plugin.
-- Reinstalling Weather, Music, Stocks or Leaderboard from the Plugin Store
-  while it is enabled asks for a display restart, as reinstalling any other
-  enabled plugin does. `POST /api/v3/plugins/install` looked for the
-  plugin's `enabled` flag under the store id (`weather`), but its config
-  section is under the id its manifest declares (`ledmatrix-weather`), so
-  `restart_required` was always false and the display kept running the
-  copy it had loaded. The check now uses the installed id.
 
 ### Scrolling
 
@@ -1081,18 +1461,6 @@ guard the import, since the loader's version check is advisory).
   processes, or turns the socket off with `off`. A non-root dev run uses a
   private per-user path under the temp directory.
 
-### Scroll speed
-
-- The Vegas Scroll Speed slider now says what the panel will do with the speed
-  it is on, and offers the nearest smooth ones to click. Only speeds that advance
-  a whole number of pixels per refresh look smooth, and which those are depends
-  on the panel (`GET /api/v3/config/scroll-speed-advice`, built on
-  `scroll_config.speed_advice()`; it uses the refresh the display measured, not
-  the `limit_refresh_rate_hz` cap). The slider steps by 1 px/s instead of 5.
-- The default 50 px/s no longer snaps to a stepped 48 px/s (2 px every 5
-  refreshes, 24 fps) on a 120 Hz panel: `solve_crisp()` now prefers 60 or 40 px/s,
-  which move one pixel at a time. 100 Hz panels are unaffected.
-
 ### Update channels
 
 - Devices no longer pick up every merge to `main`. A new setting,
@@ -1350,6 +1718,17 @@ read any of them:
 
 ### Fixes
 
+- Updating a plugin from the store no longer deletes the files it wrote
+  beside itself. A monorepo update replaces the plugin directory with the
+  fresh download and deletes the old copy, so calendar's Google OAuth files
+  (`token.pickle`, `credentials.json`) were lost on every update and the
+  calendar stopped until they were restored by hand. Before the old copy is
+  removed, the update now copies over anything the plugin's `.gitignore`
+  excludes plus known secret/state files (`*.pickle`, `token.json`,
+  `credentials.json`, `config_secrets.json`, `.pkce_code_verifier`); files the
+  new release ships are never overwritten, and byte code is not carried. A
+  plugin updated with `git pull` no longer sweeps an untracked token into the
+  auto-stash, which is never popped (`src/plugin_system/plugin_local_files.py`).
 - Quieter routine logging. Every rotation logged each mode twice
   ("Switching to mode", then "Processing mode"), and a mode with nothing to
   show added "display() returned False" and "No content to display". Those

docs/ADVANCED_FEATURES.md

@@ -649,7 +649,9 @@ When nothing is running on demand, `data.state` is
 > on-demand machinery is internal — drive it through the REST endpoints
 > above (or the web UI buttons). The API handlers
 > (`start_on_demand_display()` / `stop_on_demand_display()` in
-> `web_interface/blueprints/api_v3/display.py`) write a request into the cache
+> `web_interface/blueprints/api_v3/display.py`) send the request over the
+> display's control socket ([IPC_CONTROL_SOCKET.md](IPC_CONTROL_SOCKET.md)).
+> Only when the socket cannot carry it do they write it into the cache
 > manager under the `display_on_demand_request` key, which
 > `DisplayController._poll_on_demand_requests()`
 > (`src/display_controller.py`) picks up. A separate
@@ -747,8 +749,14 @@ keys helps troubleshoot stuck states.
   "timestamp": 1234567890.123
 }
 ```
-**Purpose:** Communication from web interface to display controller
-**When Set:** API endpoint receives request
+**Purpose:** Communication from web interface to display controller, as the
+fallback when the control socket cannot carry the request (deprecated; it
+will be removed in a later release)
+**When Set:** API endpoint receives a request and the display's control
+socket is unavailable (display stopped, or older than the socket or the
+command); some plugins also write it directly
+**Read:** once a second while the display serves the control socket (0.25 s
+without it), and only when the file changed since the last look
 **Auto-Cleared:** After processing or 1 hour TTL
 
 **2. display_on_demand_config** (No TTL)

docs/ARCHITECTURE.md

@@ -42,11 +42,11 @@ each other. They share three things:
 | State | Where | Written by | Read by |
 |---|---|---|---|
 | On-demand command | control socket `/run/ledmatrix/control.sock` ([IPC_CONTROL_SOCKET.md](IPC_CONTROL_SOCKET.md)) | web: `start_on_demand_display()` / `stop_on_demand_display()` in [`api_v3/display.py`](../web_interface/blueprints/api_v3/display.py), via [`src/ipc/client.py`](../src/ipc/client.py) | display: [`src/ipc/server.py`](../src/ipc/server.py) acks; the render thread applies it in `_poll_on_demand_requests()` |
-| On-demand request (fallback) | cache `display_on_demand_request` | web, when the socket fails; four plugins write it directly | display: `_poll_on_demand_requests()` |
+| On-demand request (fallback) | cache `display_on_demand_request` | web, only when the socket could not carry the request (`should_fall_back`); four plugins write it directly | display: `_poll_on_demand_requests()`, a `stat()` every 1 s while the socket is up (0.25 s without), read only when the file changed |
 | On-demand state | cache `display_on_demand_state` | display: `_publish_on_demand_state()` | web: `/api/v3/display/on-demand/status` |
 | Current screen | cache `display_current_state` | display | web: `/api/v3/display/current-status` |
 | Plugin errors | cache `plugin_error_snapshot` | display: `ErrorSnapshotPublisher` ([`src/error_aggregator.py`](../src/error_aggregator.py)) | web: `read_error_report()` for `/api/v3/errors/*` |
-| Error clear | cache `plugin_error_clear_request` | web | display |
+| Error clear | control socket `errors.clear`; cache `plugin_error_clear_request` as the fallback | web: `POST /api/v3/errors/clear` | display: applied before the socket answers; the mailbox on the error publisher's 5 s tick, read only when the file changed |
 | Font usage | cache `font_usage_snapshot` | display: `FontUsagePublisher` ([`src/font_usage.py`](../src/font_usage.py)) | web: Fonts tab |
 | Fetch statistics (requests per plugin and host) | cache `fetch_stats_snapshot` | display: `FetchStatsPublisher` ([`src/common/fetch_service.py`](../src/common/fetch_service.py)), at most once a minute on change | web: `read_fetch_stats()` for `/api/v3/plugins/fetch-stats` |
 | Plugin health | cache `plugin_health:<id>` | display (web writes on reset) | web: `/api/v3/plugins/health` |
@@ -58,11 +58,16 @@ each other. They share three things:
 
 The on-demand start route starts `ledmatrix.service` when it is not running
 (`start_service`, on by default) but never restarts a running one. The routes
-send the command over the display's control socket and get an ack; when that
-fails (a stopped display, one older than the socket) they write the mailbox
-instead, which the display reads every `ON_DEMAND_POLL_INTERVAL` (0.25s), from
-its dwell sleep, its render loops and Vegas's interrupt check as well as the
-main loop. Both ways end in the same handler, `_handle_on_demand_request()`.
+send the command over the display's control socket and get an ack; only when
+the socket could not carry it (a stopped display, one older than the socket
+or the command) do they write the mailbox instead. A display that had the
+request and refused it is answered with the error, not posted a mailbox
+copy. The display looks at the mailbox every
+`MAILBOX_POLL_INTERVAL_WITH_SOCKET` (1 s) while it serves the socket, and
+every `ON_DEMAND_POLL_INTERVAL` (0.25 s) without one, from its dwell sleep,
+its render loops and Vegas's interrupt check as well as the main loop; a
+look is one `stat()` unless the file changed. Both ways end in the same
+handler, `_handle_on_demand_request()`.
 The socket's handlers only queue; see [IPC_CONTROL_SOCKET.md](IPC_CONTROL_SOCKET.md)
 for the protocol, the permission model and the plan to retire the mailboxes.
 

docs/FONT_MANAGER.md

@@ -203,6 +203,7 @@ Current methods:
 | `measure_text(text, font)` | `(width, height, baseline)` |
 | `get_font_height(font)` | Line height |
 | `register_plugin_fonts(plugin_id, font_manifest)` | Register a plugin's fonts (core calls it at load) |
+| `forget_plugin_fonts(plugin_id)` | Drop a plugin's manifest fonts and their cached objects (core calls it when a plugin unloads) |
 | `clear_cache()` | Drop cached fonts and metrics |
 | `font_catalog` (attribute) | Family name → file path |
 
@@ -218,5 +219,6 @@ Removed in 3.8.0, after logging a deprecation warning on first call since
 | `get_performance_stats()` | — |
 | `set_override()`, `remove_override()`, `get_overrides()` | a font field in your plugin's config schema |
 | `get_manager_fonts()`, `get_detected_fonts()` | — |
-| `get_plugin_fonts()`, `unregister_plugin_fonts()` | — |
+| `get_plugin_fonts()` | — |
+| `unregister_plugin_fonts()` | `forget_plugin_fonts()` (core calls it on unload) |
 | `add_font()`, `remove_font()`, `validate_font()` | the web UI's Fonts tab |

docs/IPC_CONTROL_SOCKET.md

@@ -7,14 +7,18 @@ status. Stage 2 makes those commands land within a frame on every kind of
 screen, and adds `brightness.set` and `plugin.reload`. Stage 3 adds a state
 stream (`state.get`, `state.subscribe`), so the web interface reads what the
 display is doing from the socket instead of from cache files the display
-wrote to the SD card. The file mailbox and the cache keys stay as a fallback
-for one release.
+wrote to the SD card. Stage 4 makes the socket the only way a command goes
+while it works: the web interface writes a mailbox only when the socket
+cannot carry the request, `errors.clear` replaces the last command that
+always went through a mailbox, and the display looks at the mailboxes once
+a second, with a `stat()`. The file mailboxes and the cache keys stay as a
+fallback for one release.
 
 | | |
 |---|---|
 | Socket | `/run/ledmatrix/control.sock` (tmpfs) |
 | Served by | the display process ([`src/ipc/server.py`](../src/ipc/server.py)), started by `DisplayController.run()` |
-| Used by | the web interface ([`src/ipc/client.py`](../src/ipc/client.py)): `POST /api/v3/display/on-demand/start` and `/stop`, `POST /api/v3/plugins/update` (reload), `POST /api/v3/config/main` (brightness); and through [`web_interface/display_state.py`](../web_interface/display_state.py) (the state stream), `GET /api/v3/display/current-status`, `/display/on-demand/status`, `/plugins/installed` (`runtime`), `/plugins/state` and the reconciliations, `/health` (`display_loop`) |
+| Used by | the web interface ([`src/ipc/client.py`](../src/ipc/client.py)): `POST /api/v3/display/on-demand/start` and `/stop`, `POST /api/v3/plugins/update` (reload), `POST /api/v3/config/main` (brightness), `POST /api/v3/errors/clear`; and through [`web_interface/display_state.py`](../web_interface/display_state.py) (the state stream), `GET /api/v3/display/current-status`, `/display/on-demand/status`, `/plugins/installed` (`runtime`), `/plugins/state` and the reconciliations, `/health` (`display_loop`) |
 | Contract | [`src/ipc/contract.py`](../src/ipc/contract.py): messages, versions, framing and the socket path; both sides import it |
 | Override | `LEDMATRIX_CONTROL_SOCKET=/some/path.sock` for both processes, or `=off` to disable it |
 
@@ -85,6 +89,17 @@ one. Clients branch on `error.code`, never on the message text.
 | `plugin.reload` | `{plugin_id}` | `{plugin_id, reloaded: true, version, modes}` | queued, awaited (10 s) |
 | `state.get` | `{since?, epoch?}` | a state snapshot (see "The state stream") | answered directly |
 | `state.subscribe` | — | a state snapshot, then pushed `state` / `tick` events | answered directly, then a stream |
+| `errors.clear` | `{cutoff: number}` (epoch seconds, finite, ≥ 0) | `{request_id, cutoff, cleared}` | answered directly, once applied |
+
+`errors.clear` (stage 4) forgets the plugin errors the display recorded at
+or before `cutoff` and rewrites its error snapshot (`plugin_error_snapshot`)
+before it answers, so the web interface's next read already has it. The
+request `id` is the clear's id, which the snapshot reports as
+`applied_clear_id`. It is answered on the connection thread by a handler the
+display registers (`ControlServer(handlers=...)`, the contract's
+`DIRECT_COMMANDS`): the error aggregator and its publisher have their own
+locks, and nothing the render thread owns is touched. A display that has no
+handler answers `unknown_command`, as an older display does.
 
 `duration` is a number of seconds, or a numeric string. `0`, `null` or `""`
 mean "until stopped". `pinned` must be a real boolean: the REST route has
@@ -367,7 +382,9 @@ place it reads the mailbox:
   Vegas iteration is on the stack (`_apply_pending_plugin_reloads`). Until
   then the current screen ends early, as it does for a WiFi notice: the
   frame loops, the dwell and Vegas's interrupt check all treat a pending
-  reload as a reason to stop (`_screen_preempted`).
+  reload as a reason to stop (the frame loops through the Arbiter's
+  mid-screen check, `Source.RELOAD`; the dwell through
+  `_plugin_reload_pending`).
 - Only the quick half of the reload runs on the render thread
   (`_start_plugin_reload`): the plugin's modes leave the rotation, its
   config subscription is dropped, and `PluginManager.detach_plugin` takes
@@ -390,7 +407,7 @@ place it reads the mailbox:
   unloads it mid-load; a disable saved meanwhile is applied once the
   reload is done. A second reload of the same plugin runs after the first.
 
-The 0.25 s floor on the mailbox read does not apply to the queue, because
+The floor on the mailbox read (0.25 s, 1 s since stage 4) does not apply to the queue, because
 draining it costs no disk read. A queued command also lets
 `_service_pending_changes()` skip its own floor.
 
@@ -418,7 +435,7 @@ Now the queue wakes the render thread:
 
 So a command lands within a millisecond or so on a static screen and in a
 dwell, and within one frame in Vegas and on a scrolling screen. The mailbox
-keeps its old delays. Commands still run only on the render thread: the
+is slower on purpose (see "The mailboxes now"). Commands still run only on the render thread: the
 connection threads only queue them and set the event. The one exception is
 the slow half of `plugin.reload` (tearing down and loading the plugin),
 which runs on its own thread. Every change to the display's state still
@@ -436,11 +453,74 @@ bookkeeping. A client's send to the render thread waking took 0.72 ms median
 Without a socket (Windows, `LEDMATRIX_CONTROL_SOCKET=off`) the waits are the
 plain sleeps they were.
 
-**Exactly once.** A command and a mailbox write for the same request share
-one `request_id`. If the client times out after the display queued the
-command and then also writes the mailbox, the display processes the request
-once. The existing `on_demand_request_id` and processed-id checks drop the
-second copy.
+**Exactly once.** Since stage 4 the web interface writes the mailbox only
+when the display never had the request (see "When the web interface falls
+back"), so a request goes one way or the other, never both. A command and a
+mailbox write for the same request still share one `request_id`, and the
+`on_demand_request_id` and processed-id checks still drop a second copy: an
+older web interface (before stage 4) wrote the mailbox after a reply timed
+out, too. The display takes such a copy out of the mailbox when it drops it.
+
+## When the web interface falls back (stage 4)
+
+The client tells a request the display never had from one it had and then
+failed. `ControlError.sent` is True once the whole request was written to a
+connected display; a refusal the display sends before reading anything
+(`forbidden`, too many connections) carries no request id, and leaves it
+False. `src.ipc.client.should_fall_back()` is the one rule every route uses:
+
+| What happened | Example reasons | Mailbox? | The route answers |
+|---|---|---|---|
+| The display never had it | `no_socket`, `refused`, `disabled`, `unsupported`, a connect or send that timed out, `forbidden` / `busy` at the door, `invalid_request` (refused by the client itself) | yes | success, `transport: "mailbox"`, `socket_error` |
+| A display too old to know it (the upgrade case) | `unknown_command`, `unsupported_version` | yes | as above |
+| The display had it and failed | `busy` (queue full), `invalid_args`, `internal`, a timeout or hang-up after the send, `bad_response` | no | `503` (`400` for `invalid_args`), `socket_error` |
+
+A display that had the request may have applied it (a reply that timed out),
+or would refuse the mailbox copy as well (bad arguments), or is stuck and
+would not read the mailbox either (a full queue). Writing the copy anyway
+only turned that into a "success". An on-demand stop with `stop_service`
+still stops the service, which ends on-demand whatever happened.
+
+Brightness and plugin reload never had a mailbox: without the socket, the
+config watcher applies the saved brightness and a reload becomes the
+restart banner, as before.
+
+### The mailboxes now
+
+| Mailbox | Written by | Read by the display | While the socket is up |
+|---|---|---|---|
+| `display_on_demand_request` | the web interface, only on fallback; plugins that predate `BasePlugin.request_on_demand()`, or run on a core without it | the render thread, `_poll_on_demand_requests()` | looked at every 1 s (`MAILBOX_POLL_INTERVAL_WITH_SOCKET`), 0.25 s without a socket |
+| `plugin_error_clear_request` | the web interface, only on fallback | the error publisher's thread, every 5 s tick | unchanged rate |
+
+A look is one `stat()` of the mailbox file (`CacheManager.file_signature`):
+`(inode, mtime, size)`, and every write renames a new file into place, so a
+new write always looks different. `MailboxWatch` reads the file only when
+that changed since the last look, so a mailbox that holds nothing new, or
+nothing at all, costs no open and no parse. A socket command never reads or
+deletes the on-demand mailbox. A start already processed is taken out of
+the mailbox instead of being re-read until it expires.
+
+A request that comes through the on-demand mailbox while the socket is up
+is logged once per writer (`came through the file mailbox although the
+control socket is up`), which names the plugins that still write it.
+
+### Plugins in the display process
+
+A plugin asks for the screen with `BasePlugin.request_on_demand()` and gives
+it back with `end_on_demand()` (see "On-demand display" in
+[PLUGIN_API_REFERENCE.md](PLUGIN_API_REFERENCE.md)). Neither goes through
+the socket or a file: `PluginManager` hands the mailbox-shaped request,
+marked `source: 'plugin'`, to `DisplayController.submit_plugin_on_demand`,
+which queues it in memory (at most `PLUGIN_ON_DEMAND_QUEUE_SIZE`, 32) from
+whatever thread the plugin called on, and wakes the render thread through
+the socket's queue flag (`ControlServer.wake()`). The render thread applies
+it in `_drain_control_commands`, after the socket's commands, through the
+same `_handle_on_demand_request`, so it lands within a frame like a socket
+command. Without a socket it lands on the next pending-changes pass (typically
+within 0.25 s). A plugin's stop ends only a session that plugin owns. The four
+plugins that wrote the mailbox (birdnet-go, mqtt-notifications, on-air,
+pomodoro-timer) use it where the core has it and write the mailbox
+otherwise.
 
 ## Robustness
 
@@ -457,9 +537,10 @@ block the render loop or crash it:
   and the connection is closed, because the next message boundary cannot be
   found. A client that disconnects mid-message is dropped silently. No
   exception from a handler leaves the connection thread.
-- **Full queue.** When the queue is full, the client gets `busy` and falls
-  back to the mailbox. A full queue means the render thread is stuck, and the
-  systemd watchdog deals with that.
+- **Full queue.** When the queue is full, the client gets `busy`, and the web
+  interface answers `503` rather than write the mailbox, which the stuck
+  render thread would not read either. A full queue means the render thread
+  is stuck, and the systemd watchdog deals with that.
 - **Awaited commands.** The wait for an awaited command's outcome happens on
   its connection thread and is bounded (`AWAIT_SECONDS`), so a stuck render
   thread costs that client `pending` and one connection slot for at most
@@ -576,15 +657,32 @@ device never touches the live display.
      an uninstall that keeps its config, still answer `restart_required`.
      They can now use a load/unload command and report the result the same
      way the update route does.
-4. **Retire the mailboxes.** After a release in which every device has had the
-   socket, the web interface stops writing `display_on_demand_request`, and
-   the display stops polling it, logging the plugins that still write it so
-   they can move to an in-process `request_display()`. The other cache keys
-   used as messages (`plugin_error_clear_request` and the remaining
-   `display_*` keys) move to the socket or to tmpfs. The display also stops
-   writing `display_current_state`, `display_on_demand_state` and
-   `plugin_runtime_snapshot` once the web interface no longer falls back to
-   them.
+4. **The mailboxes become a fallback (done).**
+   - The web interface writes a mailbox only when the socket could not carry
+     the request (`should_fall_back`); a display that had it and failed is
+     answered as that (see "When the web interface falls back").
+   - `errors.clear` replaces `plugin_error_clear_request` as the way a clear
+     reaches the display.
+   - The display looks at the on-demand mailbox once a second while the
+     socket is up, reads either mailbox only when its file changed, and logs
+     who still writes the on-demand one (see "The mailboxes now").
+   - Not changed, deliberately: config saves (the schedule, the dim
+     schedule, plugin settings) still reach the display through
+     `config.json` and its watcher, which is the setting itself rather than
+     a message; see `config.reload` under stage 2. The preview viewer marker
+     (`/tmp/led_matrix_preview_viewer`) is a presence signal the display
+     already stats at most once a second. Plugin health and metrics resets
+     write the persisted record the display publishes and do not reach the
+     running display (their routes say so); they are not mailboxes.
+5. **Remove the mailboxes (next release).** Once every device has run a
+   display with stage 4, the web interface stops writing both mailboxes and
+   the display stops reading them. The four plugins that wrote
+   `display_on_demand_request` now have an in-process way to ask for the
+   screen (`BasePlugin.request_on_demand()` / `end_on_demand()`, see
+   "Plugins in the display process"); they keep the mailbox write only as
+   their fallback on older cores. The display also stops writing `display_current_state`,
+   `display_on_demand_state` and `plugin_runtime_snapshot` once the web
+   interface no longer falls back to them.
 
 ## Checking it on a device
 
@@ -599,7 +697,18 @@ curl -s -X POST localhost:5000/api/v3/display/on-demand/start \
 If the response says `"transport": "mailbox"`, `socket_error` gives the
 reason. `no_socket` means the display is stopped or predates the socket.
 `refused` usually means the web user is not in the socket's group, which
-takes effect when the web service restarts after the user is added.
+takes effect when the web service restarts after the user is added. A `503`
+with `"transport": "socket"` means the display had the request and did not
+take it (`busy`, `timeout`, ...): nothing was written to the mailbox.
+
+An error clear:
+
+```bash
+curl -s -X POST localhost:5000/api/v3/errors/clear \
+  -H 'Content-Type: application/json' -d '{"all":true}'
+# ... "applied": true, "transport": "socket"
+sudo journalctl -u ledmatrix | grep -E "Cleared .* plugin error|file mailbox"
+```
 
 Brightness and a plugin reload:
 

docs/PLUGIN_API_REFERENCE.md

@@ -488,6 +488,78 @@ working for the plugin itself. `get_vegas_segment_width()` read the
 `vegas_panel_count` config value, which has never affected Vegas — a card's
 width comes from `get_vegas_content()` and `vegas_width_pct`.
 
+### On-demand display
+
+A plugin that reacts to something outside the rotation (an MQTT message, a
+timer, a detection) can take the screen for it, and give it back. Both
+methods are safe from any thread, including an MQTT callback: they only
+queue the request, and the display applies it on its render thread within a
+frame or so, exactly like an on-demand start or stop from the web interface.
+
+#### `request_on_demand(mode=None, duration=None, pinned=False) -> Optional[str]`
+
+Show this plugin now.
+
+- `mode`: one of the plugin's display modes; `None` for its first.
+- `duration`: seconds before the rotation resumes; `None` (or `0`) for no
+  limit, until `end_on_demand()` or the user stops it.
+- `pinned`: stay on `mode` instead of cycling through the plugin's other
+  modes.
+
+Returns the request id once the display has queued it, or `None` when
+there is no display in this process to ask (the web interface's plugin
+manager, `scripts/check_plugin.py`) or its queue is full. A bad argument
+(a `mode` that is not a string, a `duration` that is not a number) raises
+`ValueError`.
+
+#### `end_on_demand() -> Optional[str]`
+
+Give the screen back. Ends only a session this plugin owns: a session the
+user started for another plugin, or one that already ended, is left alone.
+Returns the request id once queued, or `None` as above.
+
+#### Older cores: feature detection
+
+These methods are new after core 3.8.0 (see `CHANGELOG.md`). Before them,
+plugins wrote the `display_on_demand_request` cache key (the "mailbox")
+themselves. The display reads it only once a second while the control
+socket is up, and it will be removed in a future release (see
+[IPC_CONTROL_SOCKET.md](IPC_CONTROL_SOCKET.md), stage 5). A plugin that
+must keep working on older cores checks for the method, and writes the
+mailbox only when the method is missing or answers `None`:
+
+```python
+import time, uuid
+
+def _show_alert(self):
+    if hasattr(self, "request_on_demand") and self.request_on_demand(
+            mode="my_alert", duration=15):
+        return
+    # Older core, or no display in this process: the mailbox, as before.
+    self.cache_manager.set("display_on_demand_request", {
+        "request_id": str(uuid.uuid4()), "action": "start",
+        "plugin_id": self.plugin_id, "mode": "my_alert",
+        "duration": 15, "pinned": False, "timestamp": time.time(),
+    })
+
+def _release(self):
+    if hasattr(self, "end_on_demand") and self.end_on_demand():
+        return
+    self.cache_manager.set("display_on_demand_request", {
+        "request_id": str(uuid.uuid4()), "action": "stop",
+        "plugin_id": self.plugin_id, "timestamp": time.time(),
+    })
+```
+
+Keep `ledmatrix_min_version` where it is: the fallback is what keeps the
+plugin working on older cores. A mailbox stop ends any on-demand session,
+whoever started it; `end_on_demand()` ends only the plugin's own.
+
+Both methods answer a request id only when the plugin manager returned a
+string, so a test that gives the plugin a `MagicMock()` plugin manager gets
+`None` and exercises the mailbox path. To test the new path, set
+`plugin_manager.request_on_demand.return_value = "some-id"`.
+
 > The full source for `BasePlugin` lives in
 > `src/plugin_system/base_plugin.py`. If a method here disagrees with the
 > source, the source wins — please open an issue or PR to fix the doc.
@@ -966,6 +1038,14 @@ if info:
     self.logger.info(f"Plugin: {info['name']}, Version: {info.get('version')}")
 ```
 
+#### `request_on_demand(plugin_id, mode=None, duration=None, pinned=False)` / `end_on_demand(plugin_id)`
+
+What `BasePlugin.request_on_demand()` and `end_on_demand()` call, with the
+plugin's own id. Call those instead; see
+[On-demand display](#on-demand-display). The display controller routes them
+to itself with `set_on_demand_handler()`; a plugin manager without a
+display behind it answers `None`.
+
 #### `get_all_plugin_info() -> List[Dict[str, Any]]`
 
 Get information for all plugins.

docs/REST_API_REFERENCE.md

@@ -159,14 +159,16 @@ there an unchecked checkbox — which the browser omits — is saved as
 }
 ```
 
-`restart_required` is always true here: display hardware, rotation,
-durations and general settings take effect when the display restarts, and
-the web UI shows its restart banner on the flag. (Plugin sections saved
-through this route reach the running plugin live, like
-`POST /plugins/config`.)
+`restart_required` is true when the save changed a setting that takes
+effect when the display restarts: display hardware, rotation order,
+timezone, general settings and the rest. The web UI shows its restart banner
+on the flag. It is false when the save changed only what the running display
+applies by itself, or nothing: `brightness`, the per-mode durations
+(`duration__<mode>`, `display.display_durations`) and plugin sections, which
+reach the running plugin live, like `POST /plugins/config`.
 
-A saved `brightness` is the exception: it reaches the panel without a
-restart. The route also sends it to the running display over the control
+A saved `brightness` reaches the panel without a restart. The route also
+sends it to the running display over the control
 socket (`brightness.set`), which puts it on the panel at once, and the
 response adds `"brightness_transport": "socket"`. Otherwise it is
 `"config"`, with `brightness_socket_error` giving the reason, and the
@@ -246,7 +248,10 @@ Replace the schedule configuration.
 ```
 
 A day whose `<day>_enabled` key is absent counts as enabled, with default
-times `07:00`-`23:00`. At least one day must be enabled.
+times `07:00`-`23:00`. An enabled schedule needs at least one day enabled; a
+disabled one (`"enabled": false`) may have every day off, as
+`config.template.json` ships it. A day that is off keeps the times sent for
+it, when they are valid `HH:MM`.
 
 **Response**:
 ```json
@@ -343,7 +348,11 @@ control socket ([IPC_CONTROL_SOCKET.md](IPC_CONTROL_SOCKET.md)), and `cache`
 when it came from the `display_current_state` cache key (no socket: the
 display is stopped or older, or this is Windows). A display whose render
 loop has not refreshed its state for 120 seconds is reported with every
-field `null`, either way.
+field `null`, either way. So is a stopped display: when the socket does not
+answer and the render loop's heartbeat
+(`/run/ledmatrix/display-heartbeat.json`) is absent, stale or from a process
+that is gone, the cache's last entry is not used. A display still beating
+without a socket, Windows, or a socket switched off reads the cache.
 
 ### List Display Modes
 
@@ -455,7 +464,7 @@ Request a specific plugin to display on-demand.
 - `mode` (string, optional): Display mode name (plugin_id inferred if not provided)
 - `duration` (number, optional): Duration in seconds (0 = until stopped)
 - `pinned` (boolean, optional): Pin display (pause rotation)
-- `start_service` (boolean, optional): Start the display service if it is not running (default: true). A running service is never restarted: it picks the request up within about a quarter of a second. When false and the service is stopped, the route returns 400.
+- `start_service` (boolean, optional): Start the display service if it is not running (default: true). A running service is never restarted: it picks the request up within a frame over its control socket (within about a second through the mailbox fallback). When false and the service is stopped, the route returns 400.
 
 **Response**:
 ```json
@@ -480,10 +489,19 @@ display's control socket acknowledged it (it is queued for the render thread,
 which wakes for it and applies it within a frame; see
 [IPC_CONTROL_SOCKET.md](IPC_CONTROL_SOCKET.md)), `"mailbox"` means it was
 written to the cache mailbox the display polls, as before the socket existed.
-With `"mailbox"`, `socket_error` gives the reason the socket was not used
-(`no_socket` when the display is stopped or predates the socket, `timeout`,
-`refused`, `busy`, ...). Either way the request is applied the same way;
-`request_id` is the same id in both.
+The mailbox is used only when the socket could not carry the request. With
+`"mailbox"`, `socket_error` gives the reason (`no_socket` when the display is
+stopped or predates the socket, `refused`, a connect `timeout`,
+`unknown_command` from a display too old for the command, ...). Either way
+the request is applied the same way; `request_id` is the same id in both.
+
+When the display had the request and did not take it -- a full queue
+(`busy`), bad arguments (`invalid_args`), no answer after the request was
+sent (`timeout`, `closed`) -- the route answers `503` (`400` for
+`invalid_args`) with `status: "error"` and `data: {request_id, transport:
+"socket", socket_error}`, and writes nothing to the mailbox. The stop route
+does the same, except that with `stop_service: true` it still stops the
+service and answers success.
 
 ### Stop On-Demand Display
 
@@ -2239,13 +2257,11 @@ error with `"all": true` (`max_age_hours` is then ignored).
 }
 ```
 
-The clear is asynchronous. The web interface records a request
-(`plugin_error_clear_request` in the shared cache), and the display service
-applies it within about 5 seconds, rebuilding its counts from the errors it
-keeps and republishing. Reads hide the cleared errors from the moment the
-request is recorded. Until the display service applies an age-based clear,
-`recent_errors` and `active_patterns` are already filtered but the counts
-are the old ones, and `clear_pending` is `true`.
+The clear goes to the display service over its control socket
+(`errors.clear`, see [IPC_CONTROL_SOCKET.md](IPC_CONTROL_SOCKET.md)), which
+applies it, rebuilding its counts from the errors it keeps, and republishes
+before it answers: `applied` is `true`, `transport` is `"socket"`, and
+`cleared_count` is the display's own count.
 
 ```json
 {
@@ -2253,17 +2269,30 @@ are the old ones, and `clear_pending` is `true`.
   "data": {
     "cleared_count": 13,
     "clear_requested": true,
+    "applied": true,
+    "transport": "socket",
     "request_id": "5f0c1e...",
     "cutoff": "2026-09-23T09:59:02.310000"
   },
-  "message": "Clear of all errors requested; the display service applies it within about 5 seconds"
+  "message": "Cleared all errors"
 }
 ```
 
-`cleared_count` is how many of the reported errors the clear hides. It is
+When the socket cannot carry it (the display is stopped, or older than
+`errors.clear`) the clear is asynchronous, as before: the web interface
+records a request (`plugin_error_clear_request` in the shared cache),
+`applied` is `false` and `transport` is `"mailbox"`, and the display service
+applies it within about 5 seconds. Reads hide the cleared errors from the
+moment the request is recorded. Until the display service applies an
+age-based clear, `recent_errors` and `active_patterns` are already filtered
+but the counts are the old ones, and `clear_pending` is `true`. Then
+`cleared_count` is how many of the reported errors the clear hides, and
 `null` when that cannot be known before the display service applies it (an
-age-based clear over more errors than the report lists). A request that
-could not be written to the shared cache answers `500`.
+age-based clear over more errors than the report lists).
+
+A request that could not be written to the shared cache answers `500`. A
+display that had the request and failed it (`internal`, a timeout after the
+request was sent) answers `503`, with `context.socket_error`.
 
 ---
 
@@ -2281,7 +2310,11 @@ display snapshot. `data.status` is `healthy` or `degraded`, with
 (with `heartbeat_age_seconds`), `stalled` (no heartbeat for 60s: the panel is
 frozen even if the service is active; the status turns `degraded`), or
 `not_reported` when the display writes none (not started yet, the dev server,
-Windows), which does not affect the status. Its `source` is `socket` when the
+Windows), which does not affect the status, or `stopped` (with `source:
+"service"`) when the display service is not active, the control socket does
+not answer and there is no live heartbeat; the status then turns
+`degraded`. A platform with no control socket (Windows) or a socket switched
+off never reports `stopped`. Its `source` is `socket` when the
 age came from the display's state stream over the control socket (measured
 in memory by the display) and `heartbeat_file` when it came from
 `/run/ledmatrix/display-heartbeat.json`.
@@ -2344,8 +2377,9 @@ Replace the dim schedule. `dim_brightness` is 0-100 (default 30). In
 `per-day` mode the days can be sent either as the `days` object that GET
 returns, or as the web form's flat fields (`monday_enabled`,
 `monday_start`, `monday_end`, ...). A day that is not sent counts as
-enabled with default times `20:00`-`07:00`; at least one day must be
-enabled.
+enabled with default times `20:00`-`07:00`. As for the schedule above, an
+enabled dim schedule needs at least one day enabled and a disabled one may
+have every day off.
 
 ---
 

docs/RUN_LOOP_REDESIGN.md

@@ -36,122 +36,189 @@ Each pass, in order:
 1. `loop_pass()` (watchdog). Apply a pending plugin enable/disable, then
    any plugin reloads the control socket asked for
    (`_apply_pending_plugin_reloads`; a pending reload ends the screen
-   before it, like a WiFi notice, through `_screen_preempted`). The static
-   screen's frame sleep and the dwell wait on the socket's queue instead of
-   sleeping (`_wait_frame_interval`, `_sleep_with_plugin_updates`); without
-   a socket, as in the golden traces, they are the plain sleeps.
+   before it, like a WiFi notice, as `Source.RELOAD` at the runner's
+   service points). The static screen's frame sleep and the dwell wait on
+   the socket's queue instead of sleeping (`_wait_frame_interval`,
+   `_sleep_with_plugin_updates`); without a socket, as in the golden
+   traces, they are the plain sleeps.
 2. With no modes: dwell 1 s, next pass.
 3. Poll on-demand requests and expiry, release plugins loaded only for
    on-demand, tick plugin updates, drop an expired WiFi notice, evaluate
    the schedule (an on-demand session overrides scheduled-off), apply the
    brightness target. Then gather the Arbiter's inputs
-   (`_arbiter_inputs`) and call `Arbiter.decide()`, which picks one of
-   steps 4-6 or returns `LEGACY` for steps 7-9 (stage 2).
+   (`_arbiter_inputs`) and call `Arbiter.decide()`.
 4. **Scheduled off:** blank, dwell up to 60 s. `_blank_while_scheduled_off`
 5. **Follower:** render one frame from the leader. `_run_follower_frame`
 6. **WiFi notice** (unless on-demand): draw it, dwell 0.5 s. `_show_wifi_notice`.
-   It is also polled mid-screen (`_wifi_notice_pending`): the frame loops,
-   the dwell sleep and an interrupted Vegas iteration end within about a
-   second when one arrives, and a screen cut short resumes after it.
-7. **Live priority** (unless on-demand, or Vegas keeps live content in the
-   ticker): switch to the next live mode, or resume the rotation. A game
-   that goes live during a screen is caught sooner, by
-   `_check_live_takeover` in the frame loops and the dwell sleep (at most
-   once a second, and not while a live mode is showing).
-8. **Vegas** (unless on-demand, or live content preempts it): run one
-   iteration of up to `max_cycle_duration`. A completed iteration ends the
-   pass, and so does one that yielded for a WiFi notice or the schedule.
-   Any other interrupted one falls through to step 9 in the same pass.
-9. **One screen:** pick the mode (`_resolve_active_mode`), the plugin
-   (`_plugin_for_mode`), draw the first frame through the executor
-   (`_dispatch_first_frame`). On no content, rotate at once
-   (`_note_empty_pass`, `_skip_failed_plugin_modes`). Otherwise work out the
-   bounds (`_track_dynamic_cycle`, `_resolve_durations`,
-   `_clamp_to_on_demand`) and the frame rate (`_needs_high_fps`), run the
-   125 Hz or 1 Hz frame loop, make up the minimum duration, then pick the
-   next mode (`_advance_after_screen`).
+   It also ends a running screen within about a second (the runner's
+   service points), and a screen cut short resumes after it.
+7. **The Sources below the notice:** read whether Vegas is on and make the
+   live-priority scan (`_arbiter_inputs_below_wifi`, where run() always
+   read them), and call `decide()` again. It answers OnDemand (the
+   session's current mode), Live (the next live mode, round-robin; a game
+   that goes live during a screen takes over at the next service point, at
+   most once a second), Vegas (`LEGACY`) or Rotation. `_take_plan` applies
+   the answer: a live claim or the resume when live priority ends, the
+   on-demand index.
+8. **Vegas** (`_run_vegas_iteration`): one iteration of up to
+   `max_cycle_duration`. A completed iteration ends the pass, and so does
+   one that yielded for the schedule, a reload or a WiFi notice. Any other
+   interrupted one asks `decide()` once more (`vegas_yielded`): a game that
+   stopped the ticker, or an on-demand session that started, shows next.
+9. **One screen:** pick the plugin (`_plugin_for_mode`) and hand the plan
+   to the `ScreenRunner` (`src/screen_runner.py`). It draws the first frame
+   through the executor (`_dispatch_first_frame`), has the controller fill
+   in the plugin's durations, dynamic flag and frame policy
+   (`_complete_plan`), runs the 125 Hz or 1 Hz frame loop with a service
+   point after each frame, makes up the minimum duration, and returns an
+   `Outcome`. On `PREEMPTED` the pass ends without advancing. On no
+   content, rotate at once (`_note_empty_pass`, `_skip_failed_plugin_modes`).
+   Otherwise `ArbiterState.after()` picks the next mode
+   (`_advance_after_screen`).
 
-The helpers named above were extracted in stage 1 without changing
-behaviour. Since stage 2 the choice between steps 4, 5, 6 and the rest is
-made by `Arbiter.decide()` in `src/display_arbiter.py`. The frame loops, the
-Vegas branch and every early exit are still inline in `run()`.
-
-## Target design
+## Design
 
 ```python
 def run(self):
     while True:
-        inputs = self._drain_inputs()                 # requests, schedule, config, sync
-        plan = self.arbiter.decide(self.state, inputs, clock.now())
-        outcome = self.runner.run(plan)               # ExitReason + elapsed
-        self.state = self.state.after(plan, outcome)  # rotation, on-demand index, live resume
+        inputs = self._arbiter_inputs()                     # schedule, follower, notice
+        plan = Arbiter.decide(self._arbiter_state(), inputs, now)
+        ...                                                 # off / follower / notice
+        plan = self._take_plan(Arbiter.decide(state, self._arbiter_inputs_below_wifi(inputs), now))
+        if plan.source is Source.LEGACY:                    # Vegas, until stage 4
+            plan = self._run_vegas_iteration(...)
+        outcome = runner.run(plan, plugin)                  # ExitReason + elapsed
+        if outcome.exit_reason is not ExitReason.PREEMPTED:
+            self._advance_after_screen(plan, outcome)       # ArbiterState.after
 ```
 
+The controller's attributes (`current_display_mode`, `current_mode_index`,
+`on_demand_*`, `_live_resume_index`) stay the record that the web UI, the
+control socket and the on-demand cache read. `_arbiter_state()` snapshots
+them into a frozen `ArbiterState`; the transitions are pure methods on it,
+and the controller writes their result back (`_adopt_state`).
+
 ### Sources
 
 Each kind of content is a Source. A Source looks at the state and the
 inputs and either offers a screen or passes. The Arbiter asks them in this
 order:
 
-| Order | Source | Offers a screen when | Today |
+| Order | Source | Offers a screen when | Code |
 |---|---|---|---|
-| gate | ScheduledOff | the schedule is off and no on-demand session overrides it | step 4 |
-| 1 | Follower | a sync leader is driving this panel | step 5 |
-| 2 | OnDemand | a session is active (its mode list, index, expiry and pin) | `_resolve_active_mode` |
-| 3 | Wifi | a status message is pending and on-demand is not active | step 6 |
-| 4 | Live | a live-priority plugin has live content (round-robin across several) | step 7 |
-| 5 | Vegas | Vegas is enabled and nothing above wants the panel | step 8 |
-| 6 | Rotation | always: `available_modes[current_mode_index]` | step 9 |
+| gate | ScheduledOff | the schedule is off and no on-demand session overrides it | `decide` |
+| 1 | Follower | a sync leader is driving this panel | `decide` |
+| 2 | OnDemand | a session is active (its mode list, index, expiry and pin) | `_on_demand_plan` |
+| 3 | Wifi | a status message is pending and on-demand is not active | `decide` |
+| 4 | Live | a live-priority plugin has live content (round-robin across several) | `live_pick` |
+| 5 | Vegas | Vegas is enabled and nothing above wants the panel | `LEGACY`, run by `_run_vegas_iteration` |
+| 6 | Rotation | always: the rotation's current mode | `rotation_plan` |
 
 ScheduledOff is a gate in front of the Sources because that is how it works
 today: a scheduled-off panel stays blank even for a follower, and only an
 on-demand session overrides it.
 
+The Rotation answers `state.current_mode`, not
+`available_modes[current_mode_index]`: the two agree except where something
+moved the panel off the list and the rotation carries on from there (a live
+mode no rotation entry names, or None after a session ended with no enabled
+mode to resume to), and `run()` always showed `current_display_mode`.
+
 ### Arbiter
 
 ```python
-Arbiter.decide(state, inputs, now) -> ScreenPlan
+Arbiter.decide(state, inputs, now, running=None) -> ScreenPlan
 ```
 
 `decide` is a pure function: it does no I/O, takes no locks and does not
 sleep. It can be tested with plain tables of (state, inputs, now) mapped to
-an expected plan. It returns a `ScreenPlan`:
+an expected plan.
+
+- `ArbiterState`: the current mode; the rotation and its index; the
+  on-demand session's modes, index, expiry and pin; the live resume point;
+  whether a mid-screen takeover has not shown yet. Transitions:
+  `next_on_demand`, `showing`, `claim_live`, `release_live`, `after`.
+- `ArbiterInputs`: whether the schedule has the panel on, an on-demand
+  session, a follower, the WiFi notice, the live modes (None where no scan
+  was made), whether Vegas is on and keeps live content in its ticker,
+  whether this pass's Vegas iteration has yielded, and (mid-screen) whether
+  a plugin reload is waiting.
+- `ScreenPlan`:
 
 | Field | Meaning |
 |---|---|
 | `source` | which Source won |
-| `mode`, `plugin` | what to draw (None for a blank or follower plan) |
-| `min_duration`, `max_duration` | from `_resolve_durations` and `_clamp_to_on_demand` |
+| `mode`, `plugin` | what to draw (None for a blank or follower plan); the plugin id once resolved |
+| `min_duration`, `max_duration` | from `_resolve_durations` and the on-demand bound (`on_demand_bound`), filled in after the first frame; an on-demand plan's `max_duration` is what is left of the session at `now` |
 | `dynamic` | run until the plugin's cycle completes, between min and max |
-| `frame_policy` | today `_needs_high_fps` (125 Hz or 1 Hz); see stage 5 |
+| `frame_policy` | `HIGH_FPS` or `STATIC`, today `_needs_high_fps`; see stage 5 |
 | `preemptible_by` | the Sources allowed to interrupt this plan mid-screen |
+| `notice`, `deadline`, `ends_live` | the WiFi notice; the on-demand expiry for the bound; "live priority just ended, resume the rotation first" |
+
+`decide` cannot ask a plugin anything, so the fields a plugin answers are
+filled in by the controller after the first frame, where they were always
+read (`_complete_plan`).
+
+With `running`, `decide` answers the mid-screen question instead: `running`
+itself while the screen holds, else the plan that ends it
+(`_hold_or_preempt`), in the order the frame loops always checked:
+
+1. Live: a game went live while a non-live screen runs. It is the one
+   preemption that changes the state (the rotation moves to the live mode
+   and remembers where it was), and it is claimed even when a WiFi notice
+   is also pending; the next pass shows the notice, then the game.
+2. The panel's mode moved under the screen (on-demand started, ended or
+   changed mode; the rotation was rebuilt).
+3. The schedule turned the panel off.
+4. A WiFi notice (unless on-demand outranks it), compared with its expiry.
+5. A plugin reload is waiting (between frames only).
+
+Every screen is preemptible by the gate, OnDemand, Wifi, Live, Rotation and
+a reload (`SCREEN_PREEMPTERS`), except that a live screen leaves Live out
+(`LIVE_PREEMPTERS`): live games take turns between screens. A follower and
+Vegas are looked at only between screens.
 
 ### ScreenRunner
 
 ```python
-ScreenRunner(clock: FrameClock).run(plan) -> Outcome(exit_reason, elapsed)
+ScreenRunner(clock: FrameClock, host: ScreenHost).run(plan, plugin) -> Outcome
 ```
 
 The ScreenRunner draws the first frame (`_dispatch_first_frame`), runs the
 frame loop that the plan's frame policy selects, services pending changes
 between frames, and returns one `ExitReason`:
 
-| ExitReason | Today's equivalent (golden-trace exit) |
+| ExitReason | Golden-trace exit |
 |---|---|
 | `DURATION` | target duration reached (`duration`) |
 | `CYCLE_COMPLETE` | dynamic plugin finished after its minimum (`cycle-complete`) |
-| `EMPTY` | first frame returned False (`empty`; `raised` when display() raised inside the executor) |
+| `EMPTY` | first frame returned False, or no plugin (`empty`; `raised` when display() raised inside the executor; `no-plugin`, `breaker`) |
 | `ERROR` | the dispatch itself raised (`error`) |
 | `DISPLAY_FALSE` | a later frame returned False (`display-false`) |
-| `PREEMPTED` | another Source took the panel (`on-demand-*`, `schedule-off`, `vegas-interrupt`, ...) |
+| `PREEMPTED` | another Source took the panel (`on-demand-*`, `schedule-off`, `live`, `wifi`, ...) |
+| `RELOAD` | a plugin reload is waiting: the screen ends early but counts as shown, and the rotation advances |
 
 `PREEMPTED` replaces the five `current_display_mode != active_mode` checks.
-The runner asks the Arbiter, at the throttled service points it already has,
-whether a Source in `plan.preemptible_by` now wants the panel.
+The runner asks its host at named service points (`Checkpoint`): `FRAME`
+after each frame (and when a socket command wakes the 1 Hz wait),
+`AFTER_LOOP` / `AFTER_COMPLETED_LOOP` when the frame loop ends,
+`after_dwell` after the make-up dwell, and `FINAL` before the rotation
+advances. Each is one `decide(..., running=plan)` call
+(`DisplayController._screen_check`). The checkpoint says whether a pending
+reload counts there and when the WiFi notice file is read (`NoticeRead`):
+the read is throttled to once a second and deletes an expired file, so it
+happens exactly where the loop always read it.
 
-`FrameClock` provides `now()` and `sleep()`. In production it is
-`time.monotonic`/`time.sleep`. In the golden traces it is the fake clock
-that the harness patches in today.
+In the 125 Hz loop the live-priority scan is made before the frame's sleep
+(`_screen_service`), at the moments it always was, and weighed by the
+service point after the sleep, where the loop always decided to end the
+screen.
+
+`FrameClock` provides `time()`, `perf_counter()` and `sleep()`, the shape of
+the `time` module. In production it is `_ModuleClock`, which looks up
+`src.display_controller.time` on each call, so the golden traces' fake clock
+drives the runner as it drove the inline loops. The runner's log lines use
+the controller's logger, so they keep their source in the journal.
 
 ## Stages
 
@@ -181,13 +248,14 @@ that the harness patches in today.
   - dynamic duration (cycle complete, plugin cap, global cap)
   - live priority taking over and handing back; live round-robin
   - on-demand start/stop/expiry; pinned on-demand; a session resumed after
-    a restart
+    a restart, and one that cannot resume (its plugin did not load); a
+    request naming a live mode the plugin's live check would drop
   - schedule off and dim, with an on-demand override during downtime
   - WiFi notice; sync follower
   - Vegas, with and without `live_in_ticker`
 - Each trace row is `[start, mode, duration, exit_reason, frames,
   force_clear]`. The exit reason is the event that decided what came next.
-- All 16 tests run in under a second. The goldens were generated from
+- All 18 tests run in under a second. The goldens were generated from
   main's `run()` before any code moved.
 - Vegas uses `FakeVegas`, which implements only the contract the controller
   depends on: `run_iteration()` returns True after its duration and False
@@ -249,37 +317,84 @@ What shipped:
   Source, the dwells, the expiry comparison, the snapshot's reads, each
   dispatch in `run()`); every one failed a test.
 
-### Stage 3: ScreenRunner and `PREEMPTED`
+### Stage 3: ScreenRunner and `PREEMPTED` (done; awaiting the ledpi soak)
 
-Move the two frame loops, the make-up dwell and the dynamic-duration exit
-into `ScreenRunner.run(plan)` with an injected `FrameClock`. Replace the
-five re-checks with `PREEMPTED`. Add the OnDemand, Live and Rotation Sources
-so `LEGACY` is left meaning only Vegas.
-
-Concretely, from where stage 2 left off:
+The plan, from where stage 2 left off:
 
 1. `ArbiterState` gains the rotation index, the on-demand mode list, index,
-   expiry and pin, and the live resume point (today `current_mode_index`,
-   `on_demand_*` and the live-priority stash). `ArbiterInputs` gains the
-   live modes (`_collect_live_modes`) and whether Vegas is enabled and keeps
-   live content in the ticker.
-2. OnDemand returns its current mode with `_clamp_to_on_demand`'s bound,
-   reading `now` for the expiry. Live returns the next live mode
-   (round-robin). Rotation returns `available_modes[current_mode_index]`.
-   `ScreenPlan` gains `mode`, `plugin`, `min_duration`, `max_duration`,
-   `dynamic`, `frame_policy` and `preemptible_by`.
-3. `ScreenRunner.run(plan)` returns an `ExitReason`; `state.after(plan,
-   outcome)` replaces `_advance_after_screen` and the live-resume
-   bookkeeping. Each mid-screen check asks `decide()` whether a Source in
-   `plan.preemptible_by` now wins, so `_screen_preempted`,
-   `_check_live_takeover` and `_wifi_notice_pending` become one call.
+   expiry and pin, and the live resume point. `ArbiterInputs` gains the
+   live modes and whether Vegas is enabled and keeps live content in the
+   ticker.
+2. OnDemand returns its current mode with the session's bound, reading
+   `now` for the expiry. Live returns the next live mode (round-robin).
+   Rotation returns the rotation's mode. `ScreenPlan` gains `mode`,
+   `plugin`, `min_duration`, `max_duration`, `dynamic`, `frame_policy` and
+   `preemptible_by`.
+3. `ScreenRunner.run(plan)` returns an `ExitReason`; `state.after(outcome)`
+   replaces `_advance_after_screen`'s step and the live-resume bookkeeping.
+   Each mid-screen check asks `decide()` whether a Source in
+   `plan.preemptible_by` now wins.
 4. The control socket (`_drain_control_commands`, `_wait_for_control`) and
    state publishing stay where they are; the runner calls them at its
    service points.
 
+What shipped, one commit each: the runner; then the OnDemand, Live and
+Rotation Sources; then one `decide()` call at the service points.
+
+- `src/screen_runner.py` (on the mypy ratchet): `ScreenRunner`,
+  `FrameClock`, `ExitReason`, `Outcome`, `Checkpoint`, `NoticeRead`,
+  `Screen` and the `ScreenHost` protocol, which `DisplayController`
+  implements through `_ScreenHost` (one-line forwards to its own methods).
+  The two frame loops, the make-up dwell and the dynamic-duration exit
+  moved in unchanged, pacing included.
+- `src/display_arbiter.py`: `Source` gains `ON_DEMAND`, `LIVE`, `ROTATION`
+  and `RELOAD`; `LEGACY` means only Vegas. `FramePolicy`. `ArbiterState`
+  and `ArbiterInputs` as listed under "Arbiter". The pure helpers
+  `on_demand_bound` (`_clamp_to_on_demand`), `live_pick`
+  (`_check_live_priority`'s pick), `live_takeover` (the mid-screen claim)
+  and `rotation_plan`.
+- A pass asks `decide()` twice: once with the inputs every pass reads, and
+  once, only when nothing above the notice took the panel, with the Vegas
+  check and the live scan, read where run() always read them (the scan
+  asks every live-priority plugin, and the Vegas check applies queued
+  Vegas config, so reading them earlier, on a follower or notice pass,
+  would be a change). A Vegas iteration that yields asks a third time.
+- `_resolve_active_mode`, `_clamp_to_on_demand` and `_screen_preempted` are
+  gone. `_apply_live_priority`, `_check_live_priority`,
+  `_check_live_takeover` and `_wifi_notice_pending` remain (Vegas, the
+  dwell sleep and the tests call them), built on the same pure rules.
+- `_sleep_with_plugin_updates` keeps its own break rules. It also serves
+  the blank, the notice and the idle wait, which are not screens, and its
+  rules are edge-triggered (an on-demand session starting on the mode
+  already showing ends a dwell but not a frame loop); folding them into
+  `decide()` would change behaviour.
+
+Behaviour, checked three ways:
+
+- Golden traces: unchanged, no regeneration.
+- Every harness run in the suite (67: the goldens plus the live-takeover,
+  WiFi+live, socket-wake, plugin-reload, schedule and tick tests) was
+  captured with every sleep, `display()` call, WiFi read, live scan,
+  publish, dwell and scroll-state call logged, and diffed against
+  `origin/main`. Identical, except:
+  - a Vegas pass used to scan the live plugins twice at the same instant
+    (step 7, then step 8's "is anything live?"); it scans once;
+  - `_apply_live_priority(None)` calls that changed nothing are not made;
+  - throttled WiFi reads that returned the cached answer (no side effect)
+    after a notice had already ended the screen are not made;
+  - in the 125 Hz loop the live scan still runs before the frame's sleep,
+    but the claim is made by the service point after it, so the "live"
+    state change happens 8 ms later. The screen ends at the same frame as
+    before.
+- Tables: `test/test_display_arbiter.py` (OnDemand, Live, Vegas/Rotation,
+  `after`, the 24-row mid-screen table, `live_takeover`) and
+  `test/test_screen_runner.py` (the runner on a scripted host and fake
+  clock; the controller's service point and the reads it makes). A
+  mutation run broke each moved or new piece once; see the PR.
+
 This stage touches frame pacing (the 8 ms deadline sleep, the 1 ms yield),
-so it needs a frame soak on ledpi, A/B against main. Coordinate with
-whoever owns scroll performance (`docs/SCROLL_PERFORMANCE.md`).
+so it needs a frame soak on ledpi, A/B against main, before it merges.
+Coordinate with whoever owns scroll performance (`docs/SCROLL_PERFORMANCE.md`).
 
 ### Stage 4: Vegas as a Source
 
@@ -344,3 +459,13 @@ PR that updates the affected trace and explains why. All six are fixed:
 
 A new one found later goes the same way: record it here with the trace that
 shows it, then fix it in its own PR, not inside a restructure stage.
+
+Open:
+
+- Vegas stops for a sync follower (its interrupt check includes
+  `is_follower_active`), but the yield path never looks at a follower, so a
+  full rotation screen (20 s in the test) runs before the next pass hands
+  the panel to the leader. Found by stage 3's mutation run;
+  `test_screen_runner.py::TestThroughRun::test_vegas_yielding_to_a_follower_shows_a_rotation_screen_first`
+  pins it. Stage 4, which drops the interrupt callback, is the natural
+  place to fix it.

docs/SPORTS_UNIFICATION.md

@@ -87,10 +87,12 @@ more. Shared sports code lives in `src/common`:
 | `sports_celebration.py` | 3.7.0 | `SportsCelebrationMixin` — draws the score/win takeover; colour helpers |
 | `sports_fetch.py` | 3.7.0 | `SportsFetchMixin` — season fetch, live lookback and live-odds decisions |
 | `sports_card_wrappers.py` | 3.7.0 | `SportsCardWrappersMixin` — the game renderer's `sports_card` delegations |
-| `sports_plugin_host.py` | next release | `SportsPluginHostMixin` — the plugin class's (`manager.py`) identical helpers: Vegas weight, off-thread switch refresh |
-| `sports_live_scroll.py` | next release | `SportsLiveScrollMixin` — rebuild a live scroll strip mid-cycle, keeping the marquee's place |
-| `sports_display_rules.py` | next release | `SportsCardOptionsMixin`, `SportsGameRulesMixin` — scorebug date options, the no-favourites filter, non-favourite live dwell |
-| `sports_font_path.py` | next release | `resolve_font_path` — what the plugins' `_resolve_font_path` copies return |
+| `sports_plugin_host.py` | 3.8.0 | `SportsPluginHostMixin` — the plugin class's (`manager.py`) identical helpers: Vegas weight, off-thread switch refresh |
+| `sports_live_scroll.py` | 3.8.0 | `SportsLiveScrollMixin` — rebuild a live scroll strip mid-cycle, keeping the marquee's place |
+| `sports_display_rules.py` | 3.8.0 | `SportsCardOptionsMixin`, `SportsGameRulesMixin` — scorebug date options, the no-favourites filter, non-favourite live dwell |
+| `sports_font_path.py` | 3.8.0 | `resolve_font_path` — what the plugins' `_resolve_font_path` copies return |
+| `sports_game_over.py` | 3.8.1 | `SportsGameOverMixin` — `_is_game_really_over`, with the `FINAL_PERIOD` seam (family 5) |
+| `sports_favorites.py` | 3.8.2 | `SportsFavoritesMixin`, `SportsUpcomingFavoritesMixin`, `SportsRecentFavoritesMixin` — `_is_favorite_game` and the favourites-only picks, on the `_favorite_key` seam (family 6) |
 
 Each is described in [src/common/README.md](../src/common/README.md).
 
@@ -102,7 +104,8 @@ modules taken from the plugin copies, each a **new module** rather than growth
 on an existing one: a plugin that deletes a method copy and relies on an older
 module having gained it fails at runtime with an `AttributeError`, while a
 missing module fails at load, where the version checks can see it.
-`sports_helpers.py` holds `_favorite_key`, the override point listed below.
+`sports_helpers.py` holds `_favorite_key`, the override point listed below;
+`sports_favorites.py` is what calls it.
 Each promoted module has a parity test that compares its bodies against the
 plugin copies when `LEDMATRIX_PLUGINS` points at a checkout
 (`test_sports_helpers.py`, `test_sports_stage3_parity.py`), and
@@ -125,7 +128,7 @@ deprecation cycle.
 | `_custom_scorebug_layout(game, draw)` | Per-sport overlay on the base layout | no-op |
 | `score_phrase(points, team_abbr)` | Celebration wording (`"GOOOOAAALLL!"` vs `"TOUCHDOWN!"`). `points` is the score delta, which sports with variable-value scores use to name the play | `"<abbr> SCORES!"` — only consulted when `CelebrationMixin` is present |
 | `win_phrase(team_abbr)` | Win-celebration wording | `"<abbr> WINS!"` — mixin only |
-| `_favorite_key(game, side)` | Which view-model field identifies a team for favorites matching | `game["<side>_abbr"]` |
+| `_favorite_key(game, side)` | Which view-model field identifies a team for favorites matching. `sports_favorites` compares it, and each `favorite_teams` entry, stripped and upper-cased; a `None` matches nothing | `game["<side>_abbr"]`. nrl returns the ESPN team id, `None` when it is missing |
 | `_config_schema_path()` | Plugin's `config_schema.json` — returning it routes `_get_layout_offset` through the `src.element_style` resolver (and gives it the defaults to compare against) | `None`, i.e. the classic inline `customization.layout` read |
 | `_font_root()` | Directory to resolve `assets/fonts` against | core install root |
 
@@ -134,8 +137,7 @@ constants rather than behavior:
 
 | Attribute | Meaning | Default |
 |---|---|---|
-| `FINAL_PERIOD` | Period at/after which a zero clock can mean "over" | `4` (hockey overrides to `3`) |
-| `CLOCK_COUNTS_DOWN` | Whether `0:00` means "expired" | `True` (soccer/afl/nrl override to `False` — their clocks count up, so `0:00` is kickoff) |
+| `FINAL_PERIOD` | Period from which a 0:00 clock ends a game (`sports_game_over`) | `None`: the clock never ends a game (afl, nrl, soccer, baseball, ufc). Hockey sets `3`; basketball, football and lacrosse `4` |
 | `COALESCE_SCORING_SEQUENCE` | Fold score increments arriving during an active celebration into that one celebration | `False` (football overrides to `True` — a touchdown lands as +6, then +1 for the extra point) |
 
 ### Why these are seams and not branches
@@ -146,11 +148,14 @@ so NRL matches favorites on team ID. Flattening every plugin to abbreviations
 would silently select the wrong club for NRL users. The base declares the seam,
 NRL fills it, and core never learns the string `"nrl"`.
 
-`CLOCK_COUNTS_DOWN` exists for the same reason in the opposite direction: a
+`FINAL_PERIOD` exists for the same reason in the opposite direction: a
 soccer clock reading `0:00` means the match has not kicked off, so running the
-clock-expiry branch there would evict live games.
+clock-expiry rule there would evict live games. Those sports declare `None`,
+and so do baseball (innings, not a clock) and ufc (a bout ends only on ESPN's
+final status). One attribute covers both questions, whether the clock can end
+a game and from which period, so no separate count-down flag was added.
 
-`COALESCE_SCORING_SEQUENCE` is the third of the same kind. In football one
+`COALESCE_SCORING_SEQUENCE` is another of the same kind. In football one
 scoring play arrives as two score updates, so the follow-up must be folded into
 the first celebration; in soccer two increments a few seconds apart are two real
 goals, and folding them would swallow one. Neither default is "right" — which is
@@ -298,6 +303,49 @@ Left in the plugins, though identical:
   renderers) is already core's, in `SportsHelpersMixin`; a renderer that
   wants it can inherit that.
 
+### Family 5: the game-over check (core done; adoption waits for a release)
+
+The pilot of the method below. ledmatrix-plugins `scripts/test_game_over_check.py`
+(#621) pinned 3,115 answers across the nine plugins first; the reconcile
+(ledmatrix-plugins #625) made the five bodies one and
+changed only the cells the owner's decisions under
+[Product decisions](#product-decisions-each-family-needs) explain: ufc's
+clock rule (65 cells), baseball's dormant one (53, every one a game with a
+`period` baseball's games never carry), and a level score at 0:00 (five
+cells in hockey, basketball, football and lacrosse). The harness renders
+were pixel-identical. `src/common/sports_game_over.py` holds the body;
+`test/test_sports_game_over_parity.py` compares it, and each plugin's
+`FINAL_PERIOD`, with the plugin copies.
+
+### Family 6: favourite matching (core done; adoption waits for a release)
+
+ledmatrix-plugins `scripts/test_favourite_matching.py` (#634) pinned 204 rows
+across the nine plugins first: `_is_favorite_game` on each manager role, the
+two selection methods, the real `update()` with favourites-only on and off,
+and the INFO summary; the reconcile extends it to 217 (a lower-case and a
+padded favourite through `update()`, and the live favourite boost). The reconcile (ledmatrix-plugins
+#635) made `_is_favorite_game` one body on `SportsCore`
+(afl and soccer's `SportsUpcoming` copies and five `SportsLive` copies, all
+redundant, are gone), added `_favorite_code` beside it, and gave nrl a
+`_favorite_key` override instead of its own copies. So that a lower-case
+favourite works on a favourites-only Upcoming board, the Upcoming `update()`'s
+favourites-only pre-filter and the basketball, hockey and lacrosse live boost
+now ask `_is_favorite_game` too (a one-line change each; `update()` itself is
+family 13). Of 3,897 cells only those the decisions above explain changed:
+case and spaces in eight plugins (30-40 each), the id-less duplicate fix (6-8
+each), nrl's key (6) and its "None" match (6), and the INFO line in baseball,
+football and ufc. The harness renders were byte-identical. `src/common/sports_favorites.py` holds the
+bodies, one mixin per carrying class; `test/test_sports_favorites_parity.py`
+compares them with the plugin copies and checks that only nrl overrides
+`_favorite_key`.
+
+Left for later families: the live screens' favourites-only filter
+(`_classify_live_game` and its inline copies) and favourites-first sort still
+compare abbreviations exactly, and
+`SportsCoreSharedMixin._round_robin_favorites` groups favourites by raw
+abbreviation (or by `_team_in` where a plugin has one) instead of through
+`_favorite_key`. The result-colour helpers also wait (decision above).
+
 ### Why the method changes
 
 Byte-identical promotion has nearly run dry. Measured on ledmatrix-plugins
@@ -333,8 +381,8 @@ game-over check); the report measures each method in it. The procedure:
      line in each plugin.
    - *A per-sport fact* (hockey ends in period 3; a soccer clock counts up).
      Make it a declared class constant or override point with a default, as
-     `FINAL_PERIOD`, `CLOCK_COUNTS_DOWN`, `COALESCE_SCORING_SEQUENCE` and
-     `_favorite_key` are, and add it to the tables above. Never a sport-name
+     `FINAL_PERIOD`, `COALESCE_SCORING_SEQUENCE` and `_favorite_key` are,
+     and add it to the tables above. Never a sport-name
      branch: core must not learn sport names.
    - *A product difference*: anything a user can see (which games show, a
      colour, a date, a badge, how long a screen stays). The owner picks the
@@ -382,8 +430,8 @@ release.
 | # | Family | Methods (variants) | Why here |
 |---|---|---|---|
 | 4 | Identical sweep | `manager.py`: `_dispatch_switch_refresh`, `_favorite_team_is_live`, `get_vegas_priority_weight`, `_game_involves`, `_favorite_scan_targets`, `_favorite_scan_games`, `_get_total_games_for_manager` (all nine, 1); the live-scroll helpers `_preserving_scroll_position`, `_refresh_live_scroll_managers`, `_live_scroll_managers`, `_note_live_scroll_built`, `_live_scroll_needs_rebuild`, `_live_scroll_fields` (eight, 1). `sports.py`: `_card_option`, `_filtered_or_all`, `_effective_live_duration`, `_recent_date_text` (eight, 1). 58 identical families in all | Nothing to decide; brings `manager.py` into core as a `SportsPluginHostMixin`. `_resolve_font_path` (identical in nine `sports.py` and eight renderers) becomes `sports_font_path.resolve_font_path`, not `font_layout.resolve_asset_path`, which skips the cwd. Core side done; see [Stage 4](#stage-4-the-identical-sweep-core-done-adoption-waits-for-a-release) |
-| 5 | Game-over check | `SportsLive._is_game_really_over` (5) | Pure logic, no pixels; its seams (`FINAL_PERIOD`, `CLOCK_COUNTS_DOWN`) were designed in B1. The pilot for the procedure |
-| 6 | Favourite matching | `_is_favorite_game` (7 across three classes), `_select_games_for_display` (2: nrl), `_select_recent_games_for_display` (3) | Everything that asks "is this a favourite" goes through the 3.5.0 `_favorite_key` seam |
+| 5 | Game-over check | `SportsLive._is_game_really_over` (5) | Pure logic, no pixels; one seam, `FINAL_PERIOD`. The pilot for the procedure. Reconciled to one body and promoted as `sports_game_over`; adoption waits for the release that ships it. See [Family 5](#family-5-the-game-over-check-core-done-adoption-waits-for-a-release) |
+| 6 | Favourite matching | `_is_favorite_game` (7 across three classes), `_select_games_for_display` (2: nrl), `_select_recent_games_for_display` (3) | Everything that asks "is this a favourite" goes through the 3.5.0 `_favorite_key` seam. Reconciled to one body each and promoted as `sports_favorites`; adoption waits for the release that ships it. See [Family 6](#family-6-favourite-matching-core-done-adoption-waits-for-a-release) |
 | 7 | Other-games rotation | `_by_importance`, `_other_games_window`, `_advance_other_games_if_due` (2 each: football), `_rotate_other_games_on_display` (2: ufc) | One outlier each; football carries two fixes the other eight lack |
 | 8 | Rankings | `_fetch_team_rankings` (3), `_choose_poll` (3), `_load_division_team_ids`, `_passes_other_filters`, `_best_rank`, `_is_ranked_game` (2 each: football) | Needs 7; the rank badge and the "ranked only" filter read it |
 | 9 | Live fetch and odds | `_fetch_todays_games` (5), `_fetch_odds` (3), `_attach_odds_to_rotated_games` (3) | The prerequisite for one shared ESPN poller across plugins |
@@ -416,21 +464,28 @@ family 9 prepares.
 Owner calls to make before (or while) reconciling. Items marked *verify* are
 suspected behaviour that needs a payload or a rig to confirm first.
 
-- **5, game-over check.** Which rule each sport gets: the clock never ends a
-  game in afl, nrl and soccer (`CLOCK_COUNTS_DOWN = False`); hockey ends at
-  0:00 from period 3, basketball, football and lacrosse from period 4.
-  baseball and ufc share a copy that reads a missing clock as "0:00": dormant
-  in baseball (its games carry no `period`), and not triggered by ufc's round
-  breaks either. ESPN sends a break as `STATUS_END_OF_ROUND` with displayClock
-  `-`, not `0:00` (verified against recorded payloads; ledmatrix-plugins#580
-  pins it). Whatever rule ufc gets must not read `-` as `0:00`. Decide ufc's
-  rule: no clock rule (ESPN's `STATUS_FINAL` is the only end signal it needs;
-  this also closes a ~1 s window at the horn when the ticking clock reads
-  `0:00`), or its own final period.
-- **6, favourite matching.** NRL keeps matching favourites by team id
-  (abbreviations collide: NEW, CAN), through `_favorite_key` rather than its
-  own copies of the selection methods. Six plugins log the recent-games
-  selection at INFO; baseball, football and ufc do not.
+- **5, game-over check. Decided 2026-10-05, done:** one seam,
+  `FINAL_PERIOD`: hockey 3; basketball, football and lacrosse 4; `None` (the
+  clock never ends a game) for afl, nrl and soccer (clocks that count up),
+  baseball (its games carry no `period`, so the old rule was dormant) and
+  ufc (a bout ends only on ESPN's final status, which also closes the ~1 s
+  window at the horn when the ticking clock reads `0:00`; ESPN's round-break
+  displayClock `-` was never a zero clock, ledmatrix-plugins#580). Only a
+  non-empty clock string counts (the baseball/ufc copy read a missing clock
+  as `0:00`). A score level at 0:00 is not over: the game stays live through
+  the break before overtime, and one that really ends tied ends on its final
+  status. Baseball keeps its postponed/suspended override in `BaseballLive`.
+- **6, favourite matching. Decided 2026-10-05, done:** each side of a game is
+  named by `_favorite_key` (the abbreviation; NRL overrides it with the ESPN
+  team id, and `None` for a missing id, which fixes a favourite typed "None"
+  matching every game without one) and compared with `favorite_teams`
+  stripped and upper-cased, so " bos" matches BOS. NRL's ambiguous "NEW"
+  still matches nothing and is logged; routing the result-colour helpers
+  (`side_is_favorite`, which tint both NEW clubs) through `_favorite_key` is
+  left for a later family. The recent-games selection logs at INFO in all
+  nine. ufc stays on the shared body, dormant: its favourites are fighters,
+  which its MMA managers match themselves (a follow-up). Fix ported: only a
+  game with an id can be a duplicate in the selection methods.
 - **7, other-games rotation.** football advances the rotation window under
   `_games_lock` (update() and display() both advance it; interleaved, a
   window of games is skipped) and fixes a favourites-only pool that recomposed

docs/WEB_FRONTEND_ARCHITECTURE.md

@@ -42,7 +42,8 @@ static/v3/js/
     registry.js         page lifecycle: init/destroy on htmx swaps
     api.js              fetch wrapper for /api/v3 (JSON envelope, login redirect)
     facade.js           window.LEDMatrix and deprecated aliases
-    (later) escape.js, notify.js, dialog.js, streams.js, visibility.js,
+    visibility.js       ctx.visibility: a page's timers run only while it is on screen
+    (later) escape.js, notify.js, dialog.js, streams.js,
             store.js (the one installed-plugin store), form/renderer.js
   pages/                one module per tab partial
     cache.js            export init(root, ctx), destroy(root, ctx)
@@ -81,6 +82,20 @@ The conventions the converted pages share:
   to the module's export of the same name and warns once.
 - **Timers are cleared in `destroy()`**, the one thing `ctx.signal` cannot
   undo by itself.
+- **Polling goes through `ctx.visibility`.** A refresh that repeats
+  (`ctx.visibility.every(ms, fn)`) or work that should run only while the
+  page is on screen (`ctx.visibility.whileVisible(start, stop)`) is
+  registered there, never with a bare `setInterval`. It runs only while the
+  page's tab is the active tab and the browser tab is visible, and it ends
+  when the page is destroyed, with no code in `destroy()`.
+- **A page reports its own htmx saves.** A form whose result a page module
+  shows (an `htmx:afterRequest` listener on the page root, in place of an
+  `hx-on` attribute naming a global) carries `data-reports-result`. `app.js`
+  then leaves the server's message to the page, as it does for a form with
+  an `hx-on` after-request handler, so a save shows one notification.
+- **Server data for the module goes in `data-*` attributes**, as JSON where
+  it is structured (`data-schedule-config='{{ schedule_config | tojson }}'`),
+  not templated into a script.
 
 `core/registry.js` handles the rest:
 
@@ -103,6 +118,7 @@ Each mount gets a `ctx` object:
 | `ctx.state` | A per-mount object for the page's own state |
 | `ctx.api` | Shared service from `boot.js` |
 | `ctx.notify` | Shared service from `boot.js` |
+| `ctx.visibility` | This page's handle on `core/visibility.js` (below), made per mount by `boot.js` through the registry's `mountContext` option |
 
 A page that passes `{ signal: ctx.signal }` to `addEventListener` and
 `fetch` needs no teardown code. Its listeners and in-flight requests go
@@ -111,6 +127,30 @@ example: its delete buttons use one delegated listener, rows are built with
 `textContent` rather than markup strings, and a newer load supersedes an
 older one.
 
+### Page visibility
+
+`core/visibility.js` gives each mounted page `ctx.visibility`:
+
+| Member | What it does |
+|---|---|
+| `whileVisible(start, stop)` | Runs `start()` when the page comes on screen (at once, if it mounts on screen) and `stop()` when it leaves. Returns a function that ends the registration, running `stop()` first if needed |
+| `every(ms, fn)` | `fn()` at once, then every `ms` while on screen. The interval is cleared while hidden and restarted, with an immediate `fn()`, when the page is back. Returns the same kind of end function |
+| `isVisible()` | True while the page is on screen |
+| `tab` | The tab the page belongs to: its name, or `forPage(ctx, { tab })` |
+
+"On screen" means the page's tab is the active tab and the browser tab is
+visible. Everything a page registered ends when its `ctx.signal` aborts,
+after `destroy()`, so a swapped-out partial leaves no interval behind.
+
+The answer comes from `window.LEDVisibility` (`app-shell.js`), read at call
+time, so the page modules and the classic partials that still call it
+(Overview, Logs, Tools) agree on the active tab, and the SSE streams keep
+pausing with them. Each registration takes its own `LEDVisibility` key, so
+registrations never replace each other or a classic partial's. Without
+`LEDVisibility` (a page outside `base.html`), the browser tab's visibility
+alone decides. Moving the tracker itself into the module (the shell table
+below) changes only `core/visibility.js`.
+
 ### One facade
 
 `window.LEDMatrix` is the only global the module code adds:
@@ -239,9 +279,9 @@ are the inline script in each partial today.
 | 3 | Operation History | 293 lines, now 0 | **Done in stage 2.** Read-only list; rows drawn with `textContent`, the search debounce cleared on destroy. The "Showing x to y" counters now also reset when nothing matches |
 | 4 | Config Editor (`raw_json.html`) | 212 lines, now 0 | **Done in stage 2.** Plain textareas (no CodeMirror on this page). It defined 5 globals after all (`formatJson`, `manualValidateJson`, `validateJSON`, `saveMainConfig`, `saveSecretsConfig`); nothing else used them, and they are deprecated aliases now. The live "Invalid JSON" line no longer puts the parser's message into `innerHTML` |
 | 5 | Backup & Restore | 232 lines, now 0 | **Done in stage 2.** Its 5 globals (`exportBackup`, `loadBackupList`, `validateRestoreFile`, `clearRestore`, `runRestore`) are deprecated aliases; the buttons are delegated `data-action`s. Uploads go through `ctx.api.request(..., { body: formData })` (`api.js` gained a raw `body` option) |
-| 6 | Schedule | 193 | 2 globals used as `hx-on` response handlers. Moves `hx-on` handlers into page listeners |
-| 7 | General | 147 | `webLogin` global and the security section. The first page that touches login |
-| 8 | Display | 231 | First page with `LEDVisibility` timers: those move to a `ctx.visibility` service that stops on destroy |
+| 6 | Schedule | 193 lines, now 0 | **Done in stage 3.** Its 2 `hx-on` response handlers (`handleScheduleResponse`, `handleDimScheduleResponse`) are one `htmx:afterRequest` listener on the page root, and deprecated aliases. The forms are marked `data-reports-result` so `app.js` does not repeat the server's message. The saved schedules reach the module as JSON in `data-schedule-config` / `data-dim-schedule-config` instead of being templated into the script |
+| 7 | General | 153 lines, now 0 | **Done in stage 3.** The Security section's three forms and two buttons are delegated `data-action`s (one submit and one click listener); `window.webLogin` is a deprecated alias of an object with its five methods. Login requests go through `ctx.api`, so the login redirect is quiet. The settings form keeps its `hx-on` call to the shared `showSaveResult`, as Rotation's does |
+| 8 | Display | 292 lines (2 scripts), now 0 | **Done in stage 4.** The first page with a timer: the 5 s multi-display sync poll is `ctx.visibility.every(5000, ...)` (above), so it runs only while the tab is on screen and stops when the partial is swapped out. Its one global, `updateSyncUI` (the Role menu's `onchange`), is a deprecated alias; the Advanced section's `onclick` is a delegated `data-action="toggle-section"` that calls the shared `toggleSection`. The status poll and the scroll-speed hint go through `ctx.api` with `ctx.signal`, as does the Vegas order widget's plugin-list request. The settings form keeps its `hx-on` call to `showSaveResult` and its `onsubmit` call to `fixInvalidNumberInputs`, as Rotation's does |
 | 9 | Overview | 410 (4 scripts) | First-run surface: Getting Started, update banner, live preview. Five globals |
 | 10 | WiFi | 364 | `x-data="wifiSetup()"` is defined by its own script. Moves to `Alpine.data()` registered from the module. AP-mode first screen, so it needs the AP-mode test on a real device |
 | 11 | Fonts | 681 | Large, but self-contained (6 globals) |
@@ -258,7 +298,7 @@ the order:
 | `showNotification` | 4 versions | `core/notify.js` |
 | The modal helper | `utils/dialog.js` | `core/dialog.js` |
 | SSE streams | `app-shell.js` | `core/streams.js` |
-| `LEDVisibility` | `app-shell.js` | `core/visibility.js` |
+| `LEDVisibility` | `app-shell.js` | `core/visibility.js` (the page-facing `ctx.visibility` is there since step 8; it reads the tracker from `app-shell.js`) |
 
 Each move leaves the old global as an alias. When the last inline script is
 gone, the script re-execution in `htmx-config.js` and the "HTMX never
@@ -278,12 +318,16 @@ Unit suites need only node. They import the shipped modules directly:
 
 | Suite | Kind | What it covers |
 |---|---|---|
-| `unit/test_page_registry.js` | Unit, minimal DOM shim | The lifecycle: one init per root, destroy on swap, a veto keeps the page, swaps elsewhere leave it alone, the sweep, lazy loading, a destroy while loading, error containment |
+| `unit/test_page_registry.js` | Unit, minimal DOM shim | The lifecycle: one init per root, destroy on swap, a veto keeps the page, swaps elsewhere leave it alone, the sweep, lazy loading, a destroy while loading, error containment, `mountContext` fields per mount |
+| `dom/test_visibility_service.js` | DOM: real `LEDVisibility` from `app-shell.js`, real registry, no server | `whileVisible` and `every` start and stop with the active tab and the browser tab's visibility; no interval runs while hidden or after a swap-out; one interval after five swaps; registrations never replace each other or a classic partial's; a destroyed page registers nothing; a throwing `start()` is contained; the no-`LEDVisibility` fallback |
 | `unit/test_core_modules.js` | Unit | `api.js` (envelope, errors, abort, login redirect, path check) and `facade.js` (facade, aliases) |
 | `dom/test_cache_page.js` | DOM: real partial, real API shape | No inline script; one request per swap and per Refresh after five swaps; a cancelled request draws nothing; hostile keys stay text; delete, empty, error, network and login states |
 | `dom/test_durations_page.js` | DOM: real partial, real widget, real API shape | One plugin-list request per swap; Move down moves one place after five swaps; the swap cancels a request in flight; a late-loading widget is waited for, and a page swapped away while waiting starts nothing; hostile names stay text |
 | `dom/test_operation_history_page.js` | DOM: real partial, real API shape | One history request per swap and per Refresh; the plugin filter filled once (from `PluginAPI`'s cache when loaded); paging, filters, debounced search, Clear (one DELETE), error/network/login states, cancel on swap; hostile ids, users and errors stay text |
 | `dom/test_raw_json_page.js` | DOM: real partial, real config | One POST per Save after five swaps, to the right file; Format and Validate act once; invalid JSON never sent and its message stays text; a save survives a swap and is still reported; the old globals' entry points |
+| `dom/test_schedule_page.js` | DOM: real partial, real widget | Both pickers drawn once per swap from the saved config; after five swaps each form's answer is one notification (message, fallback, refused, non-JSON, `null`), a request from outside the forms none; the brightness label; a late widget waited for, a page swapped away while waiting draws nothing; the old globals' entry points |
+| `dom/test_display_page.js` | DOM: real partial, real widget, real `LEDVisibility`, real API shape | After five swaps one page, one sync interval, the Vegas order drawn once and each control acting once (brightness, resolution, the two show/hide toggles, the Advanced toggle, one debounced hint request); the sync poll only while on screen and never after a swap-out; sync states and hostile peer names as text, failure and login answers; a late widget waited for; `updateSyncUI`'s entry point |
+| `dom/test_general_page.js` | DOM: real partial, real widget, real API shape | The timezone picker drawn once per swap with the saved zone; the settings form left to htmx; after five swaps each Security action makes one request (create, copy, revoke and its cancel, password and its mismatch); hostile token names stay text; refused, network and login answers; a create made before a swap is still reported and draws nothing; `webLogin`'s entry points |
 | `dom/test_backup_restore_page.js` | DOM: real partial, real API shape | One request per Refresh, Delete, Export (busy button ignores a second click), Inspect and Restore after five swaps; the upload's fields and the six restore options; reads cancelled by a swap, writes not; hostile file and host names stay text; the old globals' entry points |
 | `test/web_interface/test_es_modules.py` | pytest | MIME type; `no-cache` without `?v` and immutable with it; `boot.js` loads last; every import resolves inside `core/` and `pages/`; the converted pages are exactly the registered ones, each with its module, `init`, and one root in the rendered partial; a converted partial has no `<script>` and no `onclick`; every moved global is aliased in `boot.js` and exported by its module, and no template defines it any more |
 | `test/test_field_model_parity.py` | pytest | The model against the macro for every available schema |

first_time_install.sh

@@ -91,7 +91,10 @@ if [ -r "$LM_OS_RELEASE_FILE" ]; then
     DESKTOP_DETECTED=0
     # grep without -q: -q exits at the first match, dpkg then dies of SIGPIPE,
     # and pipefail turns a found desktop into "not found".
-    if dpkg -l | grep -E "^ii.*raspberrypi-ui-mods|^ii.*lxde|^ii.*xfce|^ii.*gnome|^ii.*kde" >/dev/null; then
+    # Match on the package name only, anchored: `dpkg -l` lines include the
+    # description, so an unanchored ".*kde" matched libblockdev-* on Lite.
+    if dpkg-query -W -f='${db:Status-Abbrev} ${binary:Package}\n' 2>/dev/null \
+            | grep -E "^ii +(raspberrypi-ui-mods|lxde|xfce|gnome|kde)" >/dev/null; then
         DESKTOP_DETECTED=1
     fi
     if systemctl list-units --type=service --state=running 2>/dev/null | grep -qE "lightdm|gdm3|sddm|lxdm"; then

mypy-clean.txt

@@ -36,8 +36,10 @@ src/common/sports_card.py
 src/common/sports_card_wrappers.py
 src/common/sports_celebration.py
 src/common/sports_display_rules.py
+src/common/sports_favorites.py
 src/common/sports_fetch.py
 src/common/sports_font_path.py
+src/common/sports_game_over.py
 src/common/sports_live_scroll.py
 src/common/sports_plugin_host.py
 src/common/sports_scroll.py
@@ -58,6 +60,7 @@ src/ipc/contract.py
 src/ipc/server.py
 src/logging_config.py
 src/logo_downloader.py
+src/malloc_tuning.py
 src/matrix_support.py
 src/pi5_matrix_support.py
 src/plugin_system/__init__.py
@@ -88,6 +91,7 @@ src/plugin_system/testing/vegas.py
 src/plugin_system/vegas_elements.py
 src/redaction.py
 src/scan_order.py
+src/screen_runner.py
 src/startup_validator.py
 src/vegas_mode/__init__.py
 src/vegas_mode/config.py

run.py

@@ -14,6 +14,12 @@ project_dir = os.path.dirname(os.path.abspath(__file__))
 if project_dir not in sys.path:
     sys.path.insert(0, project_dir)
 
+# Cap glibc's malloc arenas before any thread exists (arenas already made
+# stay): the in-process twin of the unit's MALLOC_ARENA_MAX=2, for units
+# installed before that line. A no-op off glibc. See src/malloc_tuning.py.
+from src import malloc_tuning
+malloc_tuning.cap_arenas()
+
 # Under systemd the watchdog clock is already running, and start-up (plugin
 # loads, initial updates) takes far longer than the render loop's limit. Widen
 # it before anything slow is imported; the render loop narrows it again once

src/__init__.py

@@ -4,5 +4,5 @@ LEDMatrix Display System
 Core source package for the LED Matrix Display project.
 """
 
-__version__ = "3.8.0"
+__version__ = "3.8.2"
 

src/cache_manager.py

@@ -28,7 +28,7 @@ import os
 import time
 from datetime import datetime
 import pytz
-from typing import Any, Dict, List, Optional
+from typing import Any, Dict, List, Optional, Tuple
 import logging
 import threading
 import tempfile
@@ -72,6 +72,43 @@ def _outlived(record: Any, max_age: Optional[float], now: float) -> bool:
         return False
 
 
+_NOT_SEEN: Any = object()
+
+
+class MailboxWatch:
+    """Tells the poller of a mailbox key whether its file changed since the
+    last look, from one stat() (:meth:`CacheManager.file_signature`).
+
+    The display polls the mailboxes the web interface falls back to. Reading
+    one is an open and a JSON parse; with this a poll that finds the same file
+    (or none) costs a stat, and the file is read only after a new write. A
+    cache without ``file_signature`` (a test double) is read every time.
+    """
+
+    def __init__(self, key: str):
+        self.key = key
+        self._seen: Any = _NOT_SEEN
+
+    def changed(self, cache_manager: Any) -> bool:
+        """True when the poller should read the key now."""
+        signature = getattr(cache_manager, 'file_signature', None)
+        sig = signature(self.key) if callable(signature) else _NOT_SEEN
+        if sig is not None and not isinstance(sig, tuple):
+            return True   # cannot tell: read it
+        if sig is None:
+            self._seen = None
+            return False   # no file, nothing to read
+        if sig == self._seen:
+            return False
+        self._seen = sig
+        return True
+
+    def forget(self) -> None:
+        """Read the key on the next poll even if its file has not changed
+        (the last read failed)."""
+        self._seen = _NOT_SEEN
+
+
 class CacheManager:
     """Manages caching of API responses to reduce API calls."""
 
@@ -295,7 +332,25 @@ class CacheManager:
     def _get_cache_path(self, key: str) -> Optional[str]:
         """Get the path for a cache file."""
         return self._disk_cache_component.get_cache_path(key)
-        
+
+    def file_signature(self, key: str) -> Optional[Tuple[int, int, int]]:
+        """``(st_ino, st_mtime_ns, st_size)`` of ``key``'s file, or None when
+        there is no file (the key is absent, or this cache has no disk tier).
+
+        One stat(), no read: a poller of a mailbox another process writes
+        compares it with the last one it saw and reads the file only when it
+        changed. Every write replaces the file (a temp file renamed into
+        place), so a new write always has a new inode, however fast it came.
+        """
+        path = self._get_cache_path(key)
+        if not path:
+            return None
+        try:
+            st = os.stat(path)
+        except OSError:
+            return None
+        return (st.st_ino, st.st_mtime_ns, st.st_size)
+
     def get_cached_data(self, key: str, max_age: int = 300, memory_ttl: Optional[int] = None) -> Optional[Dict[str, Any]]:
         """Get data from cache (memory first, then disk) honoring TTLs.
 

src/common/README.md

@@ -44,8 +44,10 @@ Rules for the package:
 | [`sports_card_wrappers`](#sports_card_wrappers) | The game renderer's `sports_card` delegations | Yes (scoreboards) | 3.7.0 |
 | [`sports_celebration`](#sports_celebration) | Draw a scoreboard's score/win celebration | Yes (scoreboards) | 3.7.0 |
 | [`sports_display_rules`](#sports_display_rules) | Which games a scoreboard shows, for how long, and its scorebug date line | Yes (scoreboards) | 3.8.0 |
+| [`sports_favorites`](#sports_favorites) | Which games involve a favourite team, and the favourites-only picks | Yes (scoreboards) | 3.8.2 |
 | [`sports_fetch`](#sports_fetch) | Scoreboard season fetch, lookback and live-odds decisions | Yes (scoreboards) | 3.7.0 |
 | [`sports_font_path`](#sports_font_path) | Find a scoreboard's bundled font whatever the cwd | Yes (scoreboards) | 3.8.0 |
+| [`sports_game_over`](#sports_game_over) | Whether a game ESPN still lists as live has ended | Yes (scoreboards) | 3.8.1 |
 | [`sports_game_renderer`](#sports_game_renderer) | Scoreboard scroll/Vegas card geometry | Yes (scoreboards) | 3.3.0 |
 | [`sports_helpers`](#sports_helpers) | Small helpers every scoreboard `sports.py` copies | Yes (scoreboards) | 3.5.0 |
 | [`sports_live_scroll`](#sports_live_scroll) | Rebuild a live scroll strip mid-cycle without moving it | Yes (scoreboards) | 3.8.0 |
@@ -109,8 +111,11 @@ and the plugin test harness all use it. Most plugins get BDF text through
 [`espn_dates.py`](espn_dates.py). ESPN's site API rejects `dates=` ranges
 and truncates results when `limit` is above 500. `fetch_espn_scoreboard()`
 splits a range into month and day requests ESPN accepts and merges the
-results; `espn_date_chunks()`, `fetch_espn_date_chunks()`,
-`clamp_espn_limit()` and `merge_scoreboard_payloads()` are the pieces.
+results; `espn_date_chunks()`, `espn_request_chunks()`,
+`fetch_espn_date_chunks()`, `clamp_espn_limit()` and
+`merge_scoreboard_payloads()` are the pieces. A window's partial edge months
+are asked whole and trimmed to its days (US Eastern), and chunk requests share
+one process-wide cap of `ESPN_CHUNK_WORKERS` in flight.
 Every request goes through [`fetch_service`](#fetch_service), the chunks
 counted against the plugin that asked. Scoreboard plugins also bundle a copy
 for older cores.
@@ -276,6 +281,19 @@ list it before `SportsCoreSharedMixin`) and `SportsGameRulesMixin`
 `_effective_live_duration()`, the shorter dwell for a non-favourite live
 game).
 
+### sports_favorites
+
+[`sports_favorites.py`](sports_favorites.py). Sports family 6, one mixin per
+class that carried the methods: `SportsFavoritesMixin` (`SportsCore`:
+`_is_favorite_game(game)` and `_favorite_code(value)`),
+`SportsUpcomingFavoritesMixin` (`_select_games_for_display`) and
+`SportsRecentFavoritesMixin` (`_select_recent_games_for_display`). Each side
+of a game is named by `_favorite_key` (from `SportsHelpersMixin`; NRL
+overrides it with the team id) and compared with `favorite_teams` stripped and
+upper-cased. The selection methods give each favourite up to the per-team
+limit, count a game between two favourites for both, and treat only games
+with an id as possible duplicates.
+
 ### sports_fetch
 
 [`sports_fetch.py`](sports_fetch.py). `SportsFetchMixin`: the `SportsCore`
@@ -291,6 +309,16 @@ path as given when it exists (relative to the cwd), else
 `font_layout.resolve_asset_path(path)`. What the scoreboards'
 `_resolve_font_path` copies return on a core that ships it.
 
+### sports_game_over
+
+[`sports_game_over.py`](sports_game_over.py). `SportsGameOverMixin`:
+`_is_game_really_over(game)`, the `SportsLive` check that drops a game ESPN
+still lists as live (`SportsLiveSharedMixin._detect_stale_games` calls it).
+Over on a final period text, or on a 0:00 clock from period `FINAL_PERIOD`
+on unless the score is level. `FINAL_PERIOD` is a class attribute the host
+sets per sport; the default `None` means the clock never ends a game. List
+it before `SportsLiveSharedMixin`.
+
 ### sports_game_renderer
 
 [`sports_game_renderer.py`](sports_game_renderer.py).
@@ -388,7 +416,7 @@ Created by `DisplayController`; works with any plugin.
 `draw_multiline_text()`, `create_text_image()`.
 
 `draw_text_outlined(draw, xy, text, font, fill, outline_color=(0, 0, 0),
-offsets=OUTLINE_SQUARE)` (Unreleased) draws the text in `outline_color` at
+offsets=OUTLINE_SQUARE)` (3.8.1) draws the text in `outline_color` at
 each offset, then in `fill` on top: the same pixels as one `draw.text` per
 offset, but the string is rasterized once. `OUTLINE_SQUARE` is the
 eight-sided one-pixel outline the scoreboards draw, `OUTLINE_CROSS` the

src/common/espn_dates.py

@@ -26,10 +26,30 @@ A month can hold more than 500 events (college baseball's March does), and
 ESPN answers that with exactly ``limit`` events and no hint that more exist. A
 month chunk that comes back full is therefore re-asked day by day.
 
+A window's *partial* edge months are asked for whole, too, once the window
+covers ``ESPN_MONTH_COVER_MIN_DAYS`` or more of their days, and the answer is
+trimmed back to the window's days. A scoreboard's default fortnight either side
+of today (29 days, two partial months) was 29 day requests per league; it is
+now 2. Trimming needs ESPN's "game day", which is the event's start in US
+Eastern time -- checked against the live API on 2026-10-03: 417 of 417 soccer
+events across five leagues and three months (one of them spanning the end of
+daylight saving) came back from exactly the day query their Eastern date
+names. A short window (a live poll's one or two days) stays day by day, so it
+never downloads a whole month to read a day of it.
+
+Chunk requests share one process-wide budget of ``ESPN_CHUNK_WORKERS`` in
+flight, however many windows are being fetched at once. Each window used to get
+its own six, so a scoreboard starting eight leagues -- each with a recent and
+an upcoming manager -- had ~40 requests in flight, every one beyond a session's
+pool a new connection and a new DNS lookup. On a Pi whose resolver could not
+keep up, that was ~90 ``NameResolutionError`` lines within a minute of every
+start.
+
 Once a range has been rejected, later ranges skip straight to chunks for
 ``RANGE_RETRY_SECONDS`` instead of spending a doomed request first -- live
 scoreboards ask every 30 seconds. After that the range is tried again, so the
-workaround retires itself if ESPN reverts.
+workaround retires itself if ESPN reverts. A process starts inside that
+period, as if a range had just been rejected.
 
 ONE CACHE KEY PER SCOREBOARD
 ----------------------------
@@ -55,7 +75,7 @@ import re
 import threading
 import time
 from concurrent.futures import ThreadPoolExecutor
-from datetime import date, datetime, timedelta
+from datetime import date, datetime, timedelta, tzinfo
 from functools import partial
 from typing import Any, Callable, Dict, Iterable, List, Optional, Tuple, cast
 
@@ -100,16 +120,57 @@ RANGE_RETRY_SECONDS = 6 * 60 * 60
 # pool_maxsize of 10 so the shared Session never has to discard connections.
 ESPN_CHUNK_WORKERS = 6
 
+#: An edge month the window covers at least this many days of is asked for
+#: whole and trimmed, instead of one request per day (see module docstring).
+#: Below it the days are cheaper than the month: a whole month is two to
+#: three times the bytes of the half of it a fortnight window holds.
+ESPN_MONTH_COVER_MIN_DAYS = 7
+
+# Every chunk request in the process holds one of these while it is in flight
+# -- the cap is per process, not per window (see module docstring).
+_chunk_slots = threading.BoundedSemaphore(ESPN_CHUNK_WORKERS)
+
+
+def _eastern_zone() -> Optional[tzinfo]:
+    """US Eastern, the zone ESPN's ``dates=YYYYMMDD`` means, or None when
+    this Python has no time zone data (no edge month is trimmed then)."""
+    zone: Optional[tzinfo] = None
+    try:
+        from zoneinfo import ZoneInfo
+        zone = ZoneInfo("America/New_York")
+    except Exception:  # noqa: BLE001 - no zoneinfo module or no tz database
+        zone = None
+    if zone is not None:
+        return zone
+    try:
+        import pytz
+        return cast(tzinfo, pytz.timezone("America/New_York"))
+    except Exception:  # noqa: BLE001
+        return None
+
+
+_EASTERN = _eastern_zone()
+
+# What _fetch_one_chunk returns for a month that came back at the cap.
+_CAPPED: Any = object()
+
 _range_lock = threading.Lock()
-_ranges_rejected_until = 0.0
+# A process starts out assuming ranges are still rejected, as they have been
+# since 2026-09-15, and tries one again RANGE_RETRY_SECONDS in. Starting
+# from "unknown" cost one doomed range request per window at every start --
+# eleven 400s at once from a soccer board, each fetching before any had
+# answered -- to learn what every start learns.
+_ranges_rejected_until = time.monotonic() + RANGE_RETRY_SECONDS
 
 __all__ = [
     "ESPN_MAX_LIMIT",
     "ESPN_CHUNK_WORKERS",
+    "ESPN_MONTH_COVER_MIN_DAYS",
     "RANGE_RETRY_SECONDS",
     "clamp_espn_limit",
     "parse_espn_date_range",
     "espn_date_chunks",
+    "espn_request_chunks",
     "merge_scoreboard_payloads",
     "fetch_espn_date_chunks",
     "fetch_espn_scoreboard",
@@ -220,6 +281,79 @@ def espn_date_chunks(start: date, end: date) -> List[str]:
     return chunks
 
 
+def espn_request_chunks(
+    start: date,
+    end: date,
+    month_cover_min_days: Optional[int] = None,
+) -> List[Tuple[str, Optional[Tuple[date, date]]]]:
+    """The requests that fetch ``[start, end]``, as ``(dates, trim)`` pairs.
+
+    :func:`espn_date_chunks`, except that a partial edge month with
+    ``month_cover_min_days`` (default ``ESPN_MONTH_COVER_MIN_DAYS``) or more
+    of its days in the window becomes one ``YYYYMM`` request whose ``trim``
+    is the first and last of those days: its events that start outside them
+    (US Eastern) are dropped. ``trim`` is None for every other request.
+    Without time zone data nothing can be trimmed, so the edge days stay day
+    requests.
+    """
+    if month_cover_min_days is None:
+        month_cover_min_days = ESPN_MONTH_COVER_MIN_DAYS
+    planned: List[Tuple[str, Optional[Tuple[date, date]]]] = []
+    run: List[str] = []
+
+    def flush() -> None:
+        if (_EASTERN is not None and month_cover_min_days > 0
+                and len(run) >= month_cover_min_days):
+            planned.append((run[0][:6], (_parse_day(run[0]), _parse_day(run[-1]))))
+        else:
+            planned.extend((day, None) for day in run)
+        run.clear()
+
+    for chunk in espn_date_chunks(start, end):
+        if run and (len(chunk) != 8 or chunk[:6] != run[0][:6]):
+            flush()
+        if len(chunk) == 8:
+            run.append(chunk)
+        else:
+            planned.append((chunk, None))
+    flush()
+    return planned
+
+
+def _parse_day(text: str) -> date:
+    return date(int(text[:4]), int(text[4:6]), int(text[6:8]))
+
+
+def _eastern_day(stamp: Any) -> Optional[date]:
+    """The US Eastern date of an ESPN event ``date`` ("2026-10-10T11:30Z"),
+    or None when it cannot be read."""
+    if not isinstance(stamp, str) or _EASTERN is None:
+        return None
+    try:
+        moment = datetime.fromisoformat(stamp.strip().replace("Z", "+00:00"))
+    except ValueError:
+        return None
+    if moment.tzinfo is None:
+        return None
+    return moment.astimezone(_EASTERN).date()
+
+
+def _trim_to_days(payload: Any, first: date, last: date) -> Any:
+    """Drop the events of a month payload that start outside ``[first, last]``
+    (US Eastern). An event whose date cannot be read is kept: its day query
+    might well have returned it, and a game is never dropped on a guess.
+    """
+    if not isinstance(payload, dict) or not isinstance(payload.get("events"), list):
+        return payload
+    kept = []
+    for event in payload["events"]:
+        day = _eastern_day(event.get("date")) if isinstance(event, dict) else None
+        if day is None or first <= day <= last:
+            kept.append(event)
+    payload["events"] = kept
+    return payload
+
+
 def merge_scoreboard_payloads(payloads: List[Any]) -> Dict[str, Any]:
     """Fold chunk responses into one scoreboard payload.
 
@@ -250,37 +384,54 @@ def merge_scoreboard_payloads(payloads: List[Any]) -> Dict[str, Any]:
 def _fetch_one_chunk(
     session, url: str, params: Dict[str, Any], headers, timeout, logger, chunk: str,
     cache_max_age: Optional[float] = None,
-) -> Optional[Dict[str, Any]]:
+    trims: Optional[Dict[str, Tuple[date, date]]] = None,
+) -> Any:
     """GET a single ``dates=`` chunk, or None when it failed.
 
     One bad chunk must not sink the rest of the season, so every error is
     logged and swallowed here rather than raised to the gather below.
+
+    A month that comes back at the cap is truncated: it returns ``_CAPPED``,
+    its payload dropped here before it is ever held beside the others. A
+    month in ``trims`` loses its events outside the days given there.
+
+    The request holds one of the process-wide ``_chunk_slots`` while it runs.
     """
     try:
-        response = fetch_get(
-            session,
-            url,
-            params=dict(params, dates=chunk, limit=ESPN_MAX_LIMIT),
-            headers=headers,
-            timeout=timeout,
-            **_memo_kwargs(cache_max_age),
-        )
-        response.raise_for_status()
-        return cast(Optional[Dict[str, Any]], response_json(response))
+        with _chunk_slots:
+            response = fetch_get(
+                session,
+                url,
+                params=dict(params, dates=chunk, limit=ESPN_MAX_LIMIT),
+                headers=headers,
+                timeout=timeout,
+                **_memo_kwargs(cache_max_age),
+            )
+            response.raise_for_status()
+            payload = response_json(response)
     except Exception as exc:  # noqa: BLE001 - see docstring
         if logger:
             logger.warning("ESPN chunk %s failed, skipping it: %s", chunk, exc)
         return None
+    if len(chunk) == 6 and isinstance(payload, dict):
+        if len(payload.get("events") or []) >= ESPN_MAX_LIMIT:
+            return _CAPPED
+        trim = (trims or {}).get(chunk)
+        if trim is not None:
+            payload = _trim_to_days(payload, *trim)
+    return payload
 
 
 def _fetch_chunks(
     session, url: str, params: Dict[str, Any], headers, timeout, logger,
     chunks: List[str], cache_max_age: Optional[float] = None,
-) -> List[Optional[Dict[str, Any]]]:
+    trims: Optional[Dict[str, Tuple[date, date]]] = None,
+) -> List[Any]:
     """Fetch every chunk, returning payloads positionally aligned with ``chunks``.
 
     Requests go out ``ESPN_CHUNK_WORKERS`` at a time because a cold season is
-    over a hundred of them. The order they come back in is not significant --
+    over a hundred of them -- and no more than that across every window the
+    process is fetching, which ``_fetch_one_chunk``'s slot enforces. The order they come back in is not significant --
     callers keep ``chunks`` order from the returned list -- but it does mean
     the session is shared across threads, which is why this only ever issues
     GETs and never touches session state.
@@ -293,7 +444,7 @@ def _fetch_chunks(
         return []
     fetch = partial(
         _fetch_one_chunk, session, url, params, headers, timeout, logger,
-        cache_max_age=cache_max_age,
+        cache_max_age=cache_max_age, trims=trims,
     )
     if len(chunks) == 1:
         return [fetch(chunks[0])]
@@ -340,7 +491,9 @@ def fetch_espn_date_chunks(
     if span is None:
         return None
 
-    chunks = espn_date_chunks(*span)
+    planned = espn_request_chunks(*span)
+    chunks = [chunk for chunk, _ in planned]
+    trims = {chunk: trim for chunk, trim in planned if trim is not None}
     if logger:
         logger.debug(
             "Fetching ESPN date range %s as %d month/day chunks",
@@ -349,32 +502,31 @@ def fetch_espn_date_chunks(
 
     results = _fetch_chunks(
         session, url, params, headers, timeout, logger, chunks, cache_max_age,
+        trims,
     )
     attempted = len(chunks)
 
-    # A month that came back at the cap is truncated; its days replace it in
-    # place, so merged events stay in chunk order however the requests raced.
+    # A month that came back at the cap is truncated; its days (only the
+    # window's, for a trimmed edge month) replace it in place, so merged
+    # events stay in chunk order however the requests raced. Its payload was
+    # already dropped in the worker: a capped college-baseball month is ~2MB
+    # of parsed JSON, and holding four of them through ~120 day requests added
+    # ~25MB to the peak -- more than the concurrency itself. Low-memory boards
+    # (docs/LOW_MEMORY_BOARDS.md) have under 200MB of headroom.
     slots: List[Any] = results
     capped: Dict[int, List[str]] = {}
     for index, chunk in enumerate(chunks):
-        payload = slots[index]
-        if payload is None or len(chunk) != 6:
+        if slots[index] is not _CAPPED:
             continue
-        events = payload.get("events") if isinstance(payload, dict) else None
-        if len(events or []) >= ESPN_MAX_LIMIT:
-            if logger:
-                logger.info(
-                    "ESPN month %s hit the %d-event cap; re-asking it day by day",
-                    chunk, ESPN_MAX_LIMIT,
-                )
-            capped[index] = _days_of_month(chunk)
-            # Drop the truncated month now rather than after its days arrive:
-            # a capped college-baseball month is ~2MB of parsed JSON, and
-            # holding four of them through ~120 day requests added ~25MB to
-            # the peak -- more than the concurrency itself. Low-memory boards
-            # (docs/LOW_MEMORY_BOARDS.md) have under 200MB of headroom.
-            slots[index] = None
-    payload = events = None
+        if logger:
+            logger.info(
+                "ESPN month %s hit the %d-event cap; re-asking it day by day",
+                chunk, ESPN_MAX_LIMIT,
+            )
+        trim = trims.get(chunk)
+        capped[index] = (_days_of_month(chunk) if trim is None
+                         else espn_date_chunks(*trim))
+        slots[index] = None
 
     if capped:
         days = [day for index in sorted(capped) for day in capped[index]]

src/common/fetch_service.py

@@ -59,7 +59,10 @@ says how old with ``cache_max_age`` (``fetch_get(..., cache_max_age=ttl)``;
 Identical means what the validator store keys on: URL, query, effective
 headers and, for a session with cookies or auth, the session.
 
-**Counters.** Requests, merged requests, bytes, 304s, errors, HTTP errors,
+**Counters.** Requests, merged requests, bytes (``bytes`` decoded, as the
+caller reads them; ``wire_bytes`` as they crossed the network, which is
+what a metered connection pays for -- ESPN gzips, so the two differ ~14x),
+304s, errors, HTTP errors,
 adapter retries, throttled requests and seconds waited, plus requests
 answered without the network: ``memo_hits`` (the response cache) and
 ``cache_hits`` / ``legacy_cache_hits`` (a shared ESPN scoreboard cache entry,
@@ -201,6 +204,7 @@ _COUNTER_FIELDS = (
     "throttled",     # requests that waited for a host budget
     "overruns",      # requests that went after max_wait_seconds anyway
     "bytes",         # decoded response body bytes received
+    "wire_bytes",    # body bytes as they came off the socket (still compressed)
     "wait_seconds",  # time spent waiting for host budgets
     "memo_hits",     # answered from the response cache (max-age); nothing sent
     "cache_hits",    # scoreboard fetches answered from a shared ESPN cache entry
@@ -616,6 +620,30 @@ def _body_of(response: Any) -> Optional[bytes]:
     return content if isinstance(content, bytes) else None
 
 
+def _wire_bytes_of(response: Any, body: Optional[bytes]) -> int:
+    """How many body bytes came off the socket for ``response``: the
+    compressed size when the server sent gzip, which ESPN does for every
+    scoreboard (63 KB on the wire for an 865 KB college football Saturday).
+
+    urllib3's ``HTTPResponse.tell()`` counts the raw bytes read before
+    decoding. A response without one (a test double, an adapter that is not
+    urllib3) or one whose body was not read is counted at its decoded size,
+    or as 0, so the counter never claims less than it can prove.
+    """
+    if body is None:
+        return 0
+    raw = getattr(response, "raw", None)
+    tell = getattr(raw, "tell", None)
+    if callable(tell):
+        try:
+            read = tell()
+        except Exception:
+            read = None
+        if isinstance(read, int) and not isinstance(read, bool) and read > 0:
+            return read
+    return len(body)
+
+
 def _retries_of(response: Any) -> int:
     raw = getattr(response, "raw", None)
     retries = getattr(raw, "retries", None)
@@ -1117,6 +1145,7 @@ class FetchService:
                         http_errors=int(status is not None and status >= 400),
                         retries=_retries_of(response),
                         bytes=len(body) if body is not None else 0,
+                        wire_bytes=_wire_bytes_of(response, body),
                         throttled=int(waited > 0), overruns=int(overrun),
                         wait_seconds=waited)
         except Exception:

src/common/sports_favorites.py

@@ -0,0 +1,263 @@
+"""Which games involve a favourite team, and which of them to show (sports family 6).
+
+The scoreboards' favourite matching, reconciled in ledmatrix-plugins
+(family 6) from seven ``_is_favorite_game`` bodies, two
+``_select_games_for_display`` and three ``_select_recent_games_for_display``
+into one each, and copied here under their existing names:
+
+- ``SportsFavoritesMixin`` (``SportsCore``): ``_is_favorite_game(game)``,
+  asked by ``SportsCoreSharedMixin._favorites_first``, the switch-mode
+  favourite boost (``SportsHelpersMixin._next_switch_index``), the
+  non-favourite live dwell (``SportsGameRulesMixin._effective_live_duration``)
+  and the plugins' live rotation; and ``_favorite_code(value)``, the
+  normalisation both sides of every comparison go through.
+- ``SportsUpcomingFavoritesMixin`` (``SportsUpcoming``):
+  ``_select_games_for_display``, the favourites-only pick of upcoming games.
+- ``SportsRecentFavoritesMixin`` (``SportsRecent``):
+  ``_select_recent_games_for_display``, the same for finished games, most
+  recent first.
+
+Each mixin carries only what its class already had, so no manager gains a
+method it did not have.
+
+THE RULE
+--------
+Each side of a game is named by ``_favorite_key(game, side)``, the override
+point ``SportsHelpersMixin`` (``src.common.sports_helpers``) has carried since
+3.5.0: the team abbreviation by default. A sport whose abbreviations are not
+unique overrides it -- NRL returns the ESPN team id (and None when the id is
+missing), because "NEW" is both Newcastle and New Zealand. That value and every
+entry of ``favorite_teams`` are compared as ``_favorite_code`` leaves them:
+stripped and upper-cased, a blank or missing value matching nothing. So
+" bos" in the config matches BOS.
+
+The selection methods give each favourite team up to the per-team limit
+(``upcoming_games_to_show`` / ``recent_games_to_show``); a game between two
+favourites counts for both. Only a game with an id can be a duplicate: two
+games without one are two games.
+
+A new module rather than more methods on ``sports_shared`` or
+``sports_helpers``, for the reason ``sports_helpers`` gives: a missing module
+fails at load, where the version checks see it; a missing method fails
+mid-update.
+
+WHAT A HOST MUST PROVIDE
+------------------------
+Derived by walking every ``self.<attr>`` the mixins read; the host-contract
+test in ``test/test_sports_favorites.py`` fails if a read is added without
+being listed here.
+
+- ``favorite_teams`` -- the resolved favourites list (``_is_favorite_game``).
+  The selection methods are handed the list instead.
+- ``_favorite_key`` -- ``SportsHelpersMixin`` supplies the default.
+- ``_favorite_code`` -- from ``SportsFavoritesMixin``, which the Upcoming and
+  Recent classes inherit through their ``SportsCore``.
+- ``logger`` -- the selection methods log each pick at DEBUG and a summary at
+  INFO.
+- ``upcoming_games_to_show`` (Upcoming) and ``recent_games_to_show`` (Recent)
+  -- the per-team limits.
+
+The methods read the game dict's ``id`` and ``start_time_utc`` (selection),
+whatever ``_favorite_key`` reads (``home_abbr`` / ``away_abbr`` by default),
+and ``home_abbr`` / ``away_abbr`` again for the DEBUG line; any may be missing.
+
+BASE ORDER
+----------
+No other mixin defines these methods, so the position in the bases does not
+change which body runs; a method on the plugin's own class still wins. The
+mixins have no ``__init__`` and no state.
+"""
+
+import logging
+from datetime import datetime, timezone
+from typing import Callable, Dict, List, Optional
+
+
+class SportsFavoritesMixin:
+    """``SportsCore``'s favourite check. See module docstring."""
+
+    # The host contract, declared for type checking only.
+    favorite_teams: List[str]
+    _favorite_key: Callable[[Dict, str], Optional[str]]
+
+    @staticmethod
+    def _favorite_code(value) -> Optional[str]:
+        """``value`` as favourites are compared: stripped and upper-cased.
+
+        None for a missing or blank value, which matches nothing.
+        """
+        if value is None:
+            return None
+        return str(value).strip().upper() or None
+
+    def _is_favorite_game(self, game: Dict) -> bool:
+        """Does either side of this game belong to a favourite team?
+
+        ``_favorite_key`` names each side (the abbreviation; nrl overrides it
+        with the ESPN team id), and both it and ``favorite_teams`` are compared
+        as ``_favorite_code`` normalises them, so " bos" matches BOS.
+        """
+        favorites = {self._favorite_code(team) for team in self.favorite_teams or ()}
+        favorites.discard(None)
+        return any(
+            self._favorite_code(self._favorite_key(game, side)) in favorites
+            for side in ("home", "away")
+        )
+
+
+class SportsUpcomingFavoritesMixin:
+    """``SportsUpcoming``'s favourites-only pick. See module docstring."""
+
+    # The host contract, declared for type checking only.
+    logger: logging.Logger
+    upcoming_games_to_show: int
+    _favorite_key: Callable[[Dict, str], Optional[str]]
+    _favorite_code: Callable[[object], Optional[str]]
+
+    def _select_games_for_display(
+        self, processed_games: List[Dict], favorite_teams: List[str]
+    ) -> List[Dict]:
+        """
+        Single-pass game selection with proper deduplication and counting.
+
+        When a game involves two favorite teams, it counts toward BOTH teams' limits.
+        This prevents unexpected game counts from the multi-pass algorithm.
+        Teams are matched as _is_favorite_game matches them. Only a game with
+        an id can be a duplicate: two games without one are two games.
+        """
+        sorted_games = sorted(
+            processed_games,
+            key=lambda g: g.get("start_time_utc")
+            or datetime.max.replace(tzinfo=timezone.utc),
+        )
+
+        if not favorite_teams:
+            return sorted_games
+
+        selected_games = []
+        selected_ids = set()
+        team_counts: Dict[Optional[str], int] = {
+            code: 0 for code in map(self._favorite_code, favorite_teams) if code
+        }
+
+        for game in sorted_games:
+            game_id = game.get("id")
+            if game_id is not None and game_id in selected_ids:
+                continue
+
+            home = self._favorite_code(self._favorite_key(game, "home"))
+            away = self._favorite_code(self._favorite_key(game, "away"))
+
+            home_fav = home in team_counts
+            away_fav = away in team_counts
+
+            if not home_fav and not away_fav:
+                continue
+
+            home_needs = home_fav and team_counts[home] < self.upcoming_games_to_show
+            away_needs = away_fav and team_counts[away] < self.upcoming_games_to_show
+
+            if home_needs or away_needs:
+                selected_games.append(game)
+                if game_id is not None:
+                    selected_ids.add(game_id)
+                if home_fav:
+                    team_counts[home] += 1
+                if away_fav:
+                    team_counts[away] += 1
+
+                self.logger.debug(
+                    f"Selected game {game.get('away_abbr')}@{game.get('home_abbr')}: "
+                    f"team_counts={team_counts}"
+                )
+
+            if all(c >= self.upcoming_games_to_show for c in team_counts.values()):
+                self.logger.debug("All favorite teams satisfied, stopping selection")
+                break
+
+        self.logger.info(
+            f"Selected {len(selected_games)} games for {len(favorite_teams)} "
+            f"favorite teams: {team_counts}"
+        )
+        return selected_games
+
+
+class SportsRecentFavoritesMixin:
+    """``SportsRecent``'s favourites-only pick. See module docstring."""
+
+    # The host contract, declared for type checking only.
+    logger: logging.Logger
+    recent_games_to_show: int
+    _favorite_key: Callable[[Dict, str], Optional[str]]
+    _favorite_code: Callable[[object], Optional[str]]
+
+    def _select_recent_games_for_display(
+        self, processed_games: List[Dict], favorite_teams: List[str]
+    ) -> List[Dict]:
+        """
+        Single-pass game selection for recent games with proper deduplication.
+
+        When a game involves two favorite teams, it counts toward BOTH teams' limits.
+        Games are sorted by most recent first.
+        Teams are matched as _is_favorite_game matches them. Only a game with
+        an id can be a duplicate: two games without one are two games.
+        """
+        sorted_games = sorted(
+            processed_games,
+            key=lambda g: g.get("start_time_utc")
+            or datetime.min.replace(tzinfo=timezone.utc),
+            reverse=True,
+        )
+
+        if not favorite_teams:
+            return sorted_games
+
+        selected_games = []
+        selected_ids = set()
+        team_counts: Dict[Optional[str], int] = {
+            code: 0 for code in map(self._favorite_code, favorite_teams) if code
+        }
+
+        for game in sorted_games:
+            game_id = game.get("id")
+            if game_id is not None and game_id in selected_ids:
+                continue
+
+            home = self._favorite_code(self._favorite_key(game, "home"))
+            away = self._favorite_code(self._favorite_key(game, "away"))
+
+            home_fav = home in team_counts
+            away_fav = away in team_counts
+
+            if not home_fav and not away_fav:
+                continue
+
+            home_needs = home_fav and team_counts[home] < self.recent_games_to_show
+            away_needs = away_fav and team_counts[away] < self.recent_games_to_show
+
+            if home_needs or away_needs:
+                selected_games.append(game)
+                if game_id is not None:
+                    selected_ids.add(game_id)
+                if home_fav:
+                    team_counts[home] += 1
+                if away_fav:
+                    team_counts[away] += 1
+
+                self.logger.debug(
+                    f"Selected recent game {game.get('away_abbr')}@{game.get('home_abbr')}: "
+                    f"team_counts={team_counts}"
+                )
+
+            if all(c >= self.recent_games_to_show for c in team_counts.values()):
+                self.logger.debug("All favorite teams satisfied, stopping selection")
+                break
+
+        self.logger.info(
+            f"Selected {len(selected_games)} recent games for {len(favorite_teams)} "
+            f"favorite teams: {team_counts}"
+        )
+        return selected_games
+
+
+__all__ = ["SportsFavoritesMixin", "SportsUpcomingFavoritesMixin", "SportsRecentFavoritesMixin"]

src/common/sports_game_over.py

@@ -0,0 +1,125 @@
+"""Whether a game ESPN still lists as live has in fact ended (sports family 5).
+
+``SportsGameOverMixin._is_game_really_over`` is the scoreboards'
+``SportsLive._is_game_really_over``, reconciled in ledmatrix-plugins
+#625 from five bodies into one and copied here under
+its existing name. ``SportsLiveSharedMixin._detect_stale_games``
+(``src.common.sports_shared``) calls it on every live game, and the plugins'
+live-priority filters call it too, to drop a game ESPN still reports as
+in progress.
+
+A game is over when its period text says final. From period ``FINAL_PERIOD``
+on, a clock reading 0:00 ends it too, unless the score is level: a tie at the
+end of regulation goes to overtime (or a shootout), and a game that does end
+tied says final. Only a clock *string* is read ("0:00" and ":00" are zero;
+":40", "0.0" and ESPN's "-" between MMA rounds are not), and a missing or
+unreadable score leaves the decision to the clock.
+
+``FINAL_PERIOD`` is the one per-sport fact, a class attribute rather than a
+sport-name branch. The scoreboards declare it on their ``SportsLive``:
+
+- 3: hockey;
+- 4: basketball, football, lacrosse;
+- ``None`` (this default; the clock never ends a game): afl, nrl and soccer,
+  whose clocks count up; baseball, which has innings; ufc, whose bouts end
+  only on ESPN's final status.
+
+A sport can still override the method and defer to it, as baseball's
+``BaseballLive`` does to end postponed and suspended games first.
+
+A new module rather than another method on ``sports_shared``, for the reason
+``sports_helpers`` gives: a missing module fails at load, where the version
+checks see it; a missing method fails mid-update.
+
+WHAT A HOST MUST PROVIDE
+------------------------
+Derived by walking every ``self.<attr>`` the mixin reads; the host-contract
+test in ``test/test_sports_game_over.py`` fails if a read is added without
+being listed here.
+
+- ``logger`` -- a ``logging.Logger``; the method logs its verdict at DEBUG.
+- ``FINAL_PERIOD`` -- defaulted here to ``None``; set it on the host class.
+
+The method reads the game dict's ``away_abbr``, ``home_abbr``,
+``period_text``, ``period``, ``clock``, ``away_score`` and ``home_score``
+(``_extract_game_details_common``'s keys); any of them may be missing or
+null.
+
+BASE ORDER
+----------
+List the mixin before ``SportsLiveSharedMixin`` --
+``class SportsLive(SportsGameOverMixin, SportsLiveSharedMixin, SportsCore)`` --
+so the shared mixin's ``_detect_stale_games`` finds this method through the
+MRO. Neither shared mixin defines it, so the order does not change which body
+runs today; it keeps the method next to its caller should one ever be added
+there. A method on the plugin's own class still wins, and its ``super()``
+reaches this one. The mixin has no ``__init__`` and no state.
+"""
+
+import logging
+from typing import Dict, Optional
+
+
+class SportsGameOverMixin:
+    """The live manager's "is this game really over?" check. See module docstring."""
+
+    # The host contract, declared for type checking only.
+    logger: logging.Logger
+
+    #: Period from which a 0:00 clock ends a game; None: the clock never does.
+    FINAL_PERIOD: Optional[int] = None
+
+    def _is_game_really_over(self, game: Dict) -> bool:
+        """Whether a game ESPN still lists as live has in fact ended.
+
+        It has when its period text says final. From period ``FINAL_PERIOD``
+        on, a clock at 0:00 ends it too, unless the score is level: a tie at
+        the end of regulation goes to overtime, and a game that does end tied
+        says final. With ``FINAL_PERIOD = None`` the clock never ends a game.
+        """
+        game_str = f"{game.get('away_abbr')}@{game.get('home_abbr')}"
+
+        # ESPN can send the key as null, and .get()'s default only covers a
+        # missing key, so a None here crashed the whole live update.
+        raw_period_text = game.get("period_text")
+        period_text = raw_period_text.lower() if isinstance(raw_period_text, str) else ""
+        if "final" in period_text:
+            self.logger.debug(
+                f"_is_game_really_over({game_str}): "
+                f"returning True - 'final' in period_text='{period_text}'"
+            )
+            return True
+
+        # Same for a null or non-numeric period: treat it as period 0.
+        try:
+            period = int(game.get("period") or 0)
+        except (TypeError, ValueError, OverflowError):
+            period = 0
+        # Only a clock string is read: "0:00" and ":00" are zero; ":40" is not.
+        clock = game.get("clock")
+        clock_at_zero = isinstance(clock, str) and clock.replace(":", "").strip() in ("000", "00")
+
+        if self.FINAL_PERIOD is not None and period >= self.FINAL_PERIOD and clock_at_zero:
+            try:
+                tied = int(game["away_score"]) == int(game["home_score"])
+            except (KeyError, TypeError, ValueError, OverflowError):
+                tied = False  # a missing or unreadable score leaves it to the clock
+            if not tied:
+                self.logger.debug(
+                    f"_is_game_really_over({game_str}): "
+                    f"returning True - clock at 0:00 (clock='{clock}', period={period})"
+                )
+                return True
+            self.logger.debug(
+                f"_is_game_really_over({game_str}): "
+                f"returning False - tied at 0:00 (period={period}), overtime next"
+            )
+            return False
+
+        self.logger.debug(
+            f"_is_game_really_over({game_str}): returning False"
+        )
+        return False
+
+
+__all__ = ["SportsGameOverMixin"]

src/common/sports_helpers.py

@@ -34,8 +34,9 @@ first core release that ships it (see ``CHANGELOG.md``).
 
 ``_favorite_key`` is the one method not taken from the plugins: it is the
 override point from the since-removed ``src/base_classes`` sports core,
-carried here so later phases (shared celebrations and game selection) have a
-hardware-free home for the seam. No plugin defines it today and nothing in this module calls it.
+carried here as the hardware-free home for the seam. ``sports_favorites``
+calls it; nrl overrides it with the ESPN team id. Nothing in this module
+calls it.
 
 WHAT A HOST MUST PROVIDE
 ------------------------
@@ -47,8 +48,8 @@ listed here.
 - ``mode_config`` (dict) and ``logger`` -- ``_setting_int``. ``league`` is
   read with ``getattr`` for the warning text only.
 - ``games_list`` and ``current_game_index`` -- ``_next_switch_index``; plus
-  ``_is_favorite_game`` (called with a game), which stays per-plugin and is
-  only called when
+  ``_is_favorite_game`` (called with a game; ``sports_favorites`` has the
+  shared body), only called when
   ``favorite_rotation_boost`` is above 1. ``favorite_rotation_boost`` itself
   defaults to 1 on the mixin.
 - ``last_game_switch`` -- ``_reset_dwell_on_reentry``, read with ``getattr``
@@ -216,15 +217,12 @@ class SportsHelpersMixin:
         rather than a branch so core never has to learn the string "nrl"::
 
             def _favorite_key(self, game, side):
-                return str(game.get(f"{side}_id"))
+                team_id = game.get(f"{side}_id")
+                return None if team_id is None else str(team_id)
 
-        An override that stringifies should note that a missing id becomes the
-        literal ``"None"``, which would spuriously match a favorites list
-        containing that string. The default returns ``None`` for a missing
-        abbreviation, which never matches.
-
-        Carried from the since-removed ``src/base_classes`` sports core for
-        later phases; nothing in this module calls it yet.
+        It returns ``None`` for a missing id rather than ``str(None)``, which
+        would match a favourite typed "None". A ``None`` never matches.
+        ``sports_favorites`` compares the value stripped and upper-cased.
         """
         return game.get(f"{side}_abbr")
 

src/common/sports_shared.py

@@ -57,7 +57,9 @@ Methods that stay per-plugin, because they are not identical across the eight
 ``_get_layout_offset``, ``_by_importance``, ``_other_games_window``,
 ``_upcoming_date_and_time_text``, ``_extract_game_details_common``,
 ``_load_division_team_ids``, ``_get_timezone``, ``_is_favorite_game``,
-``_is_game_really_over``, ``_is_ranked_game``, ``_passes_other_filters``.
+``_is_ranked_game``, ``_passes_other_filters``. (``_is_game_really_over``,
+which ``_detect_stale_games`` below calls, was here too until the plugins
+reconciled it; it is now ``src.common.sports_game_over``.)
 
 Of the fourteen shared class constants, thirteen are identical everywhere and
 live here. Only ``_SCORE_PROBE_TEXT`` varies -- afl and basketball reach three digits
@@ -120,6 +122,32 @@ _DEFAULT_LIVE_IDLE_MAX_SECONDS = 900
 _KICKOFF_GRACE_SECONDS = 900
 #: Fallback cadence around a kickoff when the manager has no update_interval.
 _KICKOFF_POLL_FLOOR = 30
+#: How many kickoffs after the current one a live manager remembers. Only the
+#: earliest few can matter before the next look refreshes the list, so this
+#: bounds the memory without dropping a kickoff the board would wait for.
+_KICKOFF_QUEUE_MAX = 8
+
+
+def _current_scheduled_start(host: Any, now: float) -> Optional[float]:
+    """The kickoff a live manager is honouring now, promoting the next queued one.
+
+    ``_next_scheduled_start_ts`` is the kickoff being honoured: the earliest
+    one ahead of us, or one that has just passed and is inside its grace.
+    Kickoffs behind it wait in ``_later_scheduled_starts``. When the current
+    one's grace runs out, the earliest queued kickoff that is not itself past
+    its grace takes over -- including one that has already passed, so a
+    second kickoff inside the first one's grace still gets a grace of its own.
+    """
+    current: Optional[float] = getattr(host, "_next_scheduled_start_ts", None)
+    if current and current > now - _KICKOFF_GRACE_SECONDS:
+        return current
+    queued: Optional[List[float]] = getattr(host, "_later_scheduled_starts", None)
+    if queued:
+        alive = sorted(s for s in queued if s > now - _KICKOFF_GRACE_SECONDS)
+        current = alive.pop(0) if alive else None
+        host._later_scheduled_starts = alive
+        host._next_scheduled_start_ts = current
+    return current if current and current > now - _KICKOFF_GRACE_SECONDS else None
 
 
 def _resolve_font_path(path: str) -> str:
@@ -1294,11 +1322,11 @@ class SportsLiveSharedMixin:
           otherwise look like another empty check and escalate the back-off
           again, right when the game is actually starting.
         """
-        start = getattr(self, "_next_scheduled_start_ts", None)
+        now = time.time()
+        start = _current_scheduled_start(self, now)
         if not start:
             return interval
         live = getattr(self, "update_interval", None) or _KICKOFF_POLL_FLOOR
-        now = time.time()
         if now < start:
             return max(live, min(interval, int(start - now)))
         if now - start <= _KICKOFF_GRACE_SECONDS:
@@ -1313,6 +1341,16 @@ class SportsLiveSharedMixin:
         already has. Self-correcting: a stored start that has passed is
         replaced by the next one offered, so a postponed game cannot pin the
         cadence to a kickoff that never happens.
+
+        Every pending kickoff is honoured, not just the first. A kickoff that
+        arrives while an earlier one is inside its grace is queued in
+        ``_later_scheduled_starts`` (the earliest _KICKOFF_QUEUE_MAX of them)
+        and takes over when that grace ends, with a grace of its own. Keeping
+        only the one kickoff dropped the second of two favourites starting
+        within the grace of each other: it was refused while the first held
+        the slot, and refused again once it had passed, so if ESPN had not
+        flipped it live by the end of the first grace the back-off went
+        straight back to its ceiling and the game was noticed up to that late.
         """
         if not isinstance(details, dict):
             return
@@ -1329,7 +1367,7 @@ class SportsLiveSharedMixin:
         now = time.time()
         if candidate <= now:
             return
-        current = getattr(self, "_next_scheduled_start_ts", None)
+        current = _current_scheduled_start(self, now)
         # A kickoff that has only just passed is *kept*, not replaced by the
         # next one on the card. Replacing it immediately is what made the grace
         # window in _clamp_to_scheduled_start dead code: the moment 13:00 came
@@ -1339,10 +1377,20 @@ class SportsLiveSharedMixin:
         # polled at 13:00:45, found nothing live because ESPN had not flipped
         # the status yet, and then went quiet for the next quarter of an hour,
         # which is the behaviour this whole clamp exists to prevent.
-        if (current is None
-                or current <= now - _KICKOFF_GRACE_SECONDS
-                or candidate < current):
+        #
+        # Nor is it forgotten: whichever kickoff loses is queued behind the
+        # one honoured now, so it gets its own grace when that one's ends.
+        if current is None:
             self._next_scheduled_start_ts = candidate
+            return
+        if candidate == current:
+            return
+        if candidate < current:
+            self._next_scheduled_start_ts, candidate = candidate, current
+        queued = getattr(self, "_later_scheduled_starts", None) or []
+        if candidate not in queued:
+            self._later_scheduled_starts = sorted(
+                [*queued, candidate])[:_KICKOFF_QUEUE_MAX]
 
     #: How long a game that finished live is still reported by
     #: finished_games_snapshot(): long enough for the recent-games list, which

src/display_arbiter.py

@@ -1,41 +1,56 @@
 """What the panel shows next: the Arbiter of docs/RUN_LOOP_REDESIGN.md.
 
 ``Arbiter.decide(state, inputs, now)`` takes a snapshot that
-``DisplayController.run()`` gathers once per pass and returns a
-:class:`ScreenPlan` naming the Source that gets the panel. It is a pure
-function: no I/O, no clock reads (``now`` is passed in), no locks, and it
-changes nothing it is given. That is what lets a plain table of cases test
-the priority order, which used to exist only as the order of ``if`` blocks
-in ``run()``.
+``DisplayController.run()`` gathers and returns a :class:`ScreenPlan` naming
+the Source that gets the panel. It is a pure function: no I/O, no clock
+reads (``now`` is passed in), no locks, and it changes nothing it is given.
+That is what lets a plain table of cases test the priority order, which
+used to exist only as the order of ``if`` blocks in ``run()``.
 
-The full order is
+The order is
 
     ScheduledOff (a gate), Follower, OnDemand, Wifi, Live, Vegas, Rotation
 
-Stage 2 decides the gate, Follower and Wifi. Every other case returns a
-``LEGACY`` plan, meaning "carry on with run()'s existing code" (live
-priority, Vegas, then one rotation screen). OnDemand is in the order already
-because it outranks the WiFi notice: an active session is a ``LEGACY`` plan
-even when a notice is pending.
+Every Source but Vegas is decided here (stage 3). Vegas is the ``LEGACY``
+plan: the Arbiter picks it, but its iteration is still run()'s own code
+until stage 4.
 
-The Wifi Source's mid-screen rule, :func:`wifi_notice_preempts`, lives here
-too, so both of its answers -- at the top of a pass and between frames --
-come from one module.
+A pass asks twice: once with the inputs every pass reads (the gate,
+Follower, OnDemand, Wifi), and once more, only when nothing above the
+notice took the panel, with the inputs the Sources below it need (whether
+Vegas is on, the live-priority scan), read where run() always read them.
+
+``decide(..., running=plan)`` is the other question, asked by the
+ScreenRunner (src/screen_runner.py) at its service points: does a Source
+in ``plan.preemptible_by`` now take the panel from the screen that is
+running? The mid-screen rules are :func:`_hold_or_preempt`.
+
+The state transitions (the next on-demand mode, a live claim and its
+release, the rotation's step after a screen) are pure methods of
+:class:`ArbiterState`; the controller applies what they return.
 """
 
-from dataclasses import dataclass
+from dataclasses import dataclass, replace
 from enum import Enum
-from typing import Optional
+from typing import FrozenSet, Optional, Protocol, Tuple
 
 __all__ = [
     "Arbiter",
     "ArbiterInputs",
     "ArbiterState",
+    "FramePolicy",
+    "LIVE_PREEMPTERS",
     "SCHEDULED_OFF_DWELL",
+    "SCREEN_PREEMPTERS",
+    "ScreenEnd",
     "ScreenPlan",
     "Source",
     "WIFI_NOTICE_DWELL",
     "WifiNotice",
+    "live_pick",
+    "live_takeover",
+    "on_demand_bound",
+    "rotation_plan",
     "wifi_notice_preempts",
 ]
 
@@ -53,11 +68,41 @@ class Source(Enum):
 
     SCHEDULED_OFF = "scheduled-off"
     FOLLOWER = "follower"
+    ON_DEMAND = "on-demand"
     WIFI = "wifi"
-    # Not decided by the Arbiter yet: on-demand, live priority, Vegas and the
-    # rotation are still chosen by run()'s own code. Stage 3 adds the
-    # OnDemand, Live and Rotation Sources; stage 4 adds Vegas.
+    LIVE = "live"
+    # Vegas: the Arbiter picks it, but its iteration is still run()'s own
+    # code (and its interrupt callback a second copy of this order) until
+    # stage 4 makes it a Source driven frame by frame.
     LEGACY = "legacy"
+    ROTATION = "rotation"
+    # Not a screen: a plugin reload waits at the top of the loop. It ends a
+    # screen between frames (the screen counts as shown and the rotation
+    # moves on), and the next pass reloads before it draws.
+    RELOAD = "reload"
+
+
+class FramePolicy(Enum):
+    """How often a screen draws: today's two frame loops (see
+    DisplayController._needs_high_fps). Stage 5 lets plugins declare it."""
+
+    #: The 125 Hz loop, paced to an 8 ms deadline: scrolling plugins.
+    HIGH_FPS = "high-fps"
+    #: The 1 Hz loop.
+    STATIC = "static"
+
+
+class ScreenEnd(Protocol):
+    """What ArbiterState.after needs to know about how a screen ended
+    (screen_runner.Outcome, filled in by the controller)."""
+
+    @property
+    def on_demand_active(self) -> bool:
+        """An on-demand session was running when the screen ended."""
+
+    @property
+    def still_live(self) -> bool:
+        """The mode's plugin still had live content: hold the rotation."""
 
 
 @dataclass(frozen=True)
@@ -76,11 +121,122 @@ class WifiNotice:
 class ArbiterState:
     """What the Arbiter remembers between passes.
 
-    Nothing yet: the stage-2 Sources decide from the inputs alone. The
-    on-demand index, the rotation index and the live resume point move here
-    with their Sources in stage 3.
+    A snapshot of the controller's own fields, taken when decide() is
+    called (DisplayController._arbiter_state); the transitions below return
+    the next state, and the controller writes it back.
+
+    Attributes:
+        current_mode: The mode on the panel or about to be
+            (``current_display_mode``).
+        on_demand_modes: The on-demand session's modes, in the order it
+            shows them (a pinned mode already moved to the front when the
+            session started, by _apply_on_demand_pin).
+        on_demand_index: Which of them is showing.
+        on_demand_expires_at: When the session ends (wall clock), or None
+            for a session with no duration.
+        on_demand_pinned: The session was started pinned. Carried for the
+            snapshot; the pin itself is already in ``on_demand_modes``.
+        rotation: The rotation's modes (``available_modes``).
+        rotation_index: Where the rotation is (``current_mode_index``).
+        live_resume_index: Where the rotation was when live priority took
+            the panel, so it resumes there once nothing is live; None while
+            live priority holds nothing.
+        live_takeover_unshown: A mid-screen takeover chose current_mode and
+            it has not been shown yet, so the next pass must not advance the
+            live round-robin past it.
     """
 
+    current_mode: Optional[str] = None
+    on_demand_modes: Tuple[str, ...] = ()
+    on_demand_index: int = 0
+    on_demand_expires_at: Optional[float] = None
+    on_demand_pinned: bool = False
+    rotation: Tuple[str, ...] = ()
+    rotation_index: int = 0
+    live_resume_index: Optional[int] = None
+    live_takeover_unshown: bool = False
+
+    def next_on_demand(self) -> "ArbiterState":
+        """The session's next mode, wrapping round. Needs a mode list."""
+        index = (self.on_demand_index + 1) % len(self.on_demand_modes)
+        return replace(self, on_demand_index=index,
+                       current_mode=self.on_demand_modes[index])
+
+    def claim_live(self, mode: str) -> "ArbiterState":
+        """Live priority takes the panel for ``mode``.
+
+        The rotation's position is saved only on the first claim, not on
+        each re-check while the hold continues, so it resumes where live
+        priority interrupted it instead of after the live mode (which would
+        skip every mode between the two).
+        """
+        if self.current_mode == mode:
+            return self
+        resume = self.rotation_index if self.live_resume_index is None else self.live_resume_index
+        index = self.rotation.index(mode) if mode in self.rotation else self.rotation_index
+        return replace(self, current_mode=mode, rotation_index=index,
+                       live_resume_index=resume)
+
+    def after(self, outcome: "ScreenEnd") -> "ArbiterState":
+        """The state once a screen has run its course: the next mode.
+
+        An on-demand session moves to its next mode. Otherwise the rotation
+        advances -- unless the mode just shown is a live-priority mode that
+        is still live, which holds the panel. A session with no modes left
+        is ended by the controller before it asks (that is not pure: it
+        resumes the rotation and clears the cache).
+        """
+        if outcome.on_demand_active:
+            return self.next_on_demand() if self.on_demand_modes else self
+        if outcome.still_live or not self.rotation:
+            return self
+        index = (self.rotation_index + 1) % len(self.rotation)
+        return replace(self, rotation_index=index, current_mode=self.rotation[index])
+
+    def release_live(self) -> "ArbiterState":
+        """Nothing is live any more: the rotation resumes where it was."""
+        if self.live_resume_index is None or not self.rotation:
+            return self
+        index = self.live_resume_index % len(self.rotation)
+        return replace(self, current_mode=self.rotation[index], rotation_index=index,
+                       live_resume_index=None)
+
+    def showing(self, plan: "ScreenPlan") -> "ArbiterState":
+        """The state once ``plan`` is on the panel.
+
+        An on-demand plan puts the session's index on the mode it shows (an
+        index past the end of a shortened list starts it again at 0).
+        """
+        state = replace(self, current_mode=plan.mode)
+        if plan.source is Source.ON_DEMAND and self.on_demand_modes:
+            state = replace(state, on_demand_index=_on_demand_index(self))
+        return state
+
+
+def _on_demand_index(state: ArbiterState) -> int:
+    """The session's index, or 0 once it is past the end of its list."""
+    index = state.on_demand_index
+    return index if index < len(state.on_demand_modes) else 0
+
+
+def on_demand_bound(min_duration: float, max_duration: float,
+                    deadline: Optional[float],
+                    now: float) -> Optional[Tuple[float, float]]:
+    """Shorten a screen's (min, max) seconds to what is left of a timed
+    on-demand session ending at ``deadline``. None when nothing is left.
+
+    The OnDemand Source's bound, applied after the screen's first frame,
+    where it always was (``now`` is read then).
+    """
+    if deadline is None:
+        return min_duration, max_duration
+    remaining = max(0.0, deadline - now)
+    min_duration = min(min_duration, remaining)
+    max_duration = min(max_duration, remaining)
+    if max_duration <= 0:
+        return None
+    return min_duration, max_duration
+
 
 @dataclass(frozen=True)
 class ArbiterInputs:
@@ -95,57 +251,122 @@ class ArbiterInputs:
             when it could win (the panel is on, and neither a follower nor
             on-demand outranks it), because reading it has side effects: a
             1 Hz throttle and deleting an expired file.
+        live_modes: The modes with live content, from a live-priority scan,
+            in registration order; None when no scan was made (on-demand,
+            Vegas keeping live content in its ticker, a throttled
+            mid-screen check). A scan asks every live-priority plugin, so it
+            is made only where run() always made it.
+        vegas_enabled: Vegas mode is on (and no on-demand session holds it
+            off).
+        vegas_live_in_ticker: Vegas keeps live content in its ticker
+            instead of yielding the panel to it.
+        vegas_yielded: This pass's Vegas iteration has run and yielded, so
+            the Vegas Source passes and the screen it fell through to is
+            decided.
+        reload_pending: Mid-screen only: a plugin reload is waiting for the
+            top of the loop, at a service point where that ends the screen.
     """
 
     schedule_on: bool
     on_demand_active: bool
     follower_active: bool
     wifi_notice: Optional[WifiNotice] = None
+    live_modes: Optional[Tuple[str, ...]] = None
+    vegas_enabled: bool = False
+    vegas_live_in_ticker: bool = False
+    vegas_yielded: bool = False
+    reload_pending: bool = False
 
 
 @dataclass(frozen=True)
 class ScreenPlan:
     """The Arbiter's answer for one pass.
 
+    decide() is pure, so it cannot ask a plugin anything: the fields a
+    plugin answers (its durations, whether it runs a dynamic cycle, how
+    often it draws) are filled in by the controller after the screen's first
+    frame, when they have always been read (DisplayController.complete_plan).
+
     Attributes:
         source: The Source that gets the panel.
+        mode: The display mode to draw (None for a blank, follower or notice).
+        plugin: The id of the plugin drawing ``mode``, once resolved.
+        min_duration: Seconds the screen runs at least (dynamic duration).
         max_duration: How long the plan holds the panel, in seconds, at most
             (its dwell ends early when what the panel should show changes).
-            None when the Source paces itself: a follower frame, or LEGACY.
+            None when the Source paces itself (a follower frame, Vegas), and
+            for a rotation or live plan until its first frame.
+        dynamic: Run until the plugin's cycle completes, between min and max.
+        frame_policy: Which frame loop the screen runs.
+        preemptible_by: The Sources that may end the screen mid-way.
         notice: The WiFi notice to draw, for a WIFI plan.
+        deadline: For an on-demand plan, when the session ends (wall
+            clock): after the first frame the screen's durations are cut to
+            what is left (:func:`on_demand_bound`).
+        ends_live: Nothing is live any more and live priority had
+            interrupted the rotation: taking this plan resumes the rotation
+            where it was (ArbiterState.release_live) before it shows.
     """
 
     source: Source
+    mode: Optional[str] = None
+    plugin: Optional[str] = None
+    min_duration: Optional[float] = None
     max_duration: Optional[float] = None
+    dynamic: bool = False
+    frame_policy: Optional[FramePolicy] = None
+    preemptible_by: FrozenSet[Source] = frozenset()
     notice: Optional[WifiNotice] = None
+    deadline: Optional[float] = None
+    ends_live: bool = False
 
 
 SCHEDULED_OFF_PLAN = ScreenPlan(Source.SCHEDULED_OFF, max_duration=SCHEDULED_OFF_DWELL)
 FOLLOWER_PLAN = ScreenPlan(Source.FOLLOWER)
-LEGACY_PLAN = ScreenPlan(Source.LEGACY)
+RELOAD_PLAN = ScreenPlan(Source.RELOAD)
+
+#: What may end a screen mid-way: the schedule, an on-demand session
+#: starting or ending, a WiFi notice, a live game, the rotation moving
+#: under the screen, and a plugin reload. Not a follower or Vegas: those
+#: are only looked at between screens.
+SCREEN_PREEMPTERS: FrozenSet[Source] = frozenset(
+    {Source.SCHEDULED_OFF, Source.ON_DEMAND, Source.WIFI, Source.LIVE, Source.ROTATION,
+     Source.RELOAD})
+
+#: A live screen is not preempted by Live: live games take turns between
+#: screens, never mid-screen.
+LIVE_PREEMPTERS: FrozenSet[Source] = SCREEN_PREEMPTERS - {Source.LIVE}
 
 
 class Arbiter:
     """Decides which Source gets the panel. Stateless; see the module docstring."""
 
     @staticmethod
-    def decide(state: ArbiterState, inputs: ArbiterInputs, now: float) -> ScreenPlan:
+    def decide(state: ArbiterState, inputs: ArbiterInputs, now: float,
+               running: Optional[ScreenPlan] = None) -> ScreenPlan:
         """The plan for this pass, from the Sources in priority order.
 
+        With ``running``, the question is the ScreenRunner's at one of its
+        service points instead: does a Source in ``running.preemptible_by``
+        now take the panel from that screen? The answer is ``running``
+        itself (the same object) while it holds, else the plan that ends it.
+        See :func:`_hold_or_preempt` for the rules.
+
         Args:
-            state: What the Arbiter remembers between passes (nothing yet).
+            state: What the Arbiter remembers between passes.
             inputs: This pass's snapshot.
-            now: Wall-clock time of the snapshot. No stage-2 Source reads it:
-                the top-of-pass WiFi check takes the notice as read, and only
-                the mid-screen check (:func:`wifi_notice_preempts`) compares
-                it with the expiry. It is in the signature for the Sources
-                stage 3 adds (on-demand expiry, durations).
+            now: Wall-clock time of the snapshot. The OnDemand Source reads
+                it for what is left of a timed session, and the mid-screen
+                WiFi rule (:func:`wifi_notice_preempts`) to compare with the
+                notice's expiry. The top-of-pass WiFi check does not: it
+                takes the notice as read.
+            running: The screen on the panel, for a mid-screen check.
 
         Returns:
-            The winning Source's plan, or LEGACY_PLAN when the winner is one
-            run() still decides itself.
+            The winning Source's plan (LEGACY for Vegas), or ``running``.
         """
-        del state, now  # not read by the stage-2 Sources; see the docstring
+        if running is not None:
+            return _hold_or_preempt(state, inputs, now, running)
 
         # ScheduledOff is a gate, not a Source: a scheduled-off panel stays
         # blank even for a follower, and only an on-demand session overrides
@@ -157,17 +378,161 @@ class Arbiter:
         if inputs.follower_active:
             return FOLLOWER_PLAN
 
-        # 2. OnDemand: decided by run() until stage 3. It outranks the notice.
+        # 2. OnDemand: the session's current mode. It outranks the notice.
         if inputs.on_demand_active:
-            return LEGACY_PLAN
+            return _on_demand_plan(state, now)
 
         # 3. Wifi: a pending notice, held for one short dwell per pass.
         if inputs.wifi_notice is not None:
             return ScreenPlan(Source.WIFI, max_duration=WIFI_NOTICE_DWELL,
                               notice=inputs.wifi_notice)
 
-        # 4-6. Live, Vegas, Rotation: still run()'s own code.
-        return LEGACY_PLAN
+        # 4. Live: the next live game, round-robin across several. With
+        # nothing live, a rotation that live priority interrupted resumes.
+        ends_live = False
+        if _live_applies(inputs):
+            pick = live_pick(inputs.live_modes, state.current_mode,
+                             advance=not state.live_takeover_unshown)
+            if pick is not None:
+                return ScreenPlan(Source.LIVE, mode=pick, preemptible_by=LIVE_PREEMPTERS)
+            ends_live = state.live_resume_index is not None and bool(state.rotation)
+
+        # 5. Vegas: one iteration of the ticker, run by run()'s own code
+        # until stage 4. Passes once this pass's iteration has yielded.
+        if inputs.vegas_enabled and not inputs.vegas_yielded:
+            return ScreenPlan(Source.LEGACY, ends_live=ends_live)
+
+        # 6. Rotation: the rotation's current mode (after the resume, when
+        # live priority just ended).
+        return rotation_plan(state.release_live() if ends_live else state,
+                             ends_live=ends_live)
+
+
+def _hold_or_preempt(state: ArbiterState, inputs: ArbiterInputs, now: float,
+                     running: ScreenPlan) -> ScreenPlan:
+    """The mid-screen rules: ``running``, or the plan that ends it.
+
+    What the frame loops used to check one by one (_check_live_takeover,
+    then _screen_preempted with _wifi_notice_pending in it, before stage 3),
+    in their order:
+
+    1. Live: a game went live while a non-live screen runs (the inputs
+       carry a scan only when one was due, at most once a second). Checked
+       first because it is the one preemption that changes the state -- the
+       rotation moves to the live mode and remembers where it was -- and it
+       still happens when a WiFi notice is also pending: the next pass then
+       shows the notice, and the game after it.
+    2. The panel's mode moved under the screen: an on-demand session
+       started, ended or changed mode, or the rotation was rebuilt (a
+       plugin enabled, disabled or reloaded).
+    3. The schedule turned the panel off.
+    4. A WiFi notice arrived (unless on-demand outranks it), compared with
+       its expiry because the read throttle can hand back a stale one.
+    5. A plugin reload is waiting at the top of the loop.
+
+    A follower and Vegas are never mid-screen preemptions; they are looked
+    at between screens.
+    """
+    by = running.preemptible_by
+    if Source.LIVE in by:
+        takeover = live_takeover(state, inputs)
+        if takeover is not None:
+            return ScreenPlan(Source.LIVE, mode=takeover, preemptible_by=LIVE_PREEMPTERS)
+    if state.current_mode != running.mode:
+        source = Source.ON_DEMAND if inputs.on_demand_active else Source.ROTATION
+        if source in by:
+            return ScreenPlan(source, mode=state.current_mode, preemptible_by=SCREEN_PREEMPTERS)
+    if (Source.SCHEDULED_OFF in by and not inputs.schedule_on
+            and not inputs.on_demand_active):
+        return SCHEDULED_OFF_PLAN
+    notice = inputs.wifi_notice
+    if (Source.WIFI in by and notice is not None
+            and wifi_notice_preempts(notice, inputs.on_demand_active, now)):
+        return ScreenPlan(Source.WIFI, max_duration=WIFI_NOTICE_DWELL, notice=notice)
+    if Source.RELOAD in by and inputs.reload_pending:
+        return RELOAD_PLAN
+    return running
+
+
+def live_takeover(state: ArbiterState, inputs: ArbiterInputs) -> Optional[str]:
+    """The live mode that takes the panel mid-screen, or None.
+
+    The first live mode, when a scan found one and the panel is not on a
+    live mode already. Never while on-demand holds the panel, while it is
+    scheduled off, or while Vegas keeps live content in its ticker.
+    """
+    if not _live_applies(inputs) or inputs.on_demand_active or not inputs.schedule_on:
+        return None
+    live = inputs.live_modes
+    if not live or state.current_mode in live:
+        return None
+    return live[0]
+
+
+def _on_demand_plan(state: ArbiterState, now: float) -> ScreenPlan:
+    """The OnDemand Source: the session's current mode.
+
+    ``max_duration`` is what is left of a timed session at ``now`` (None
+    without a duration); ``deadline`` carries the expiry so the bound can be
+    applied again after the first frame. A session with no modes left (its
+    plugin was unloaded under it) gets a plan with no mode: the controller
+    ends the session and shows the rotation's mode instead.
+    """
+    modes = state.on_demand_modes
+    if not modes:
+        return ScreenPlan(Source.ON_DEMAND)
+    expires_at = state.on_demand_expires_at
+    remaining = None if expires_at is None else max(0.0, expires_at - now)
+    return ScreenPlan(Source.ON_DEMAND, mode=modes[_on_demand_index(state)],
+                      max_duration=remaining, deadline=expires_at,
+                      preemptible_by=SCREEN_PREEMPTERS)
+
+
+def rotation_plan(state: ArbiterState, ends_live: bool = False) -> ScreenPlan:
+    """The Rotation Source: the mode the rotation is on.
+
+    That is ``state.current_mode``, which is ``rotation[rotation_index]``
+    except where something moved the panel off the list and the rotation
+    carries on from there: a live mode no rotation entry names, or None
+    when a session ended with no enabled mode to resume to.
+    """
+    return ScreenPlan(Source.ROTATION, mode=state.current_mode, ends_live=ends_live,
+                      preemptible_by=SCREEN_PREEMPTERS)
+
+
+def _live_applies(inputs: ArbiterInputs) -> bool:
+    """Whether the Live Source has a say: a scan was made, and Vegas is not
+    keeping live content in its ticker (where the live plugin takes extra
+    turns in the marquee instead of the panel)."""
+    if inputs.live_modes is None:
+        return False
+    return not (inputs.vegas_enabled and inputs.vegas_live_in_ticker)
+
+
+def live_pick(live_modes: Optional[Tuple[str, ...]], current_mode: Optional[str],
+              advance: bool) -> Optional[str]:
+    """The live mode to show, or None when nothing is live.
+
+    When several plugins are live at once this round-robins between them, so
+    the panel alternates each dwell instead of pinning to the first one
+    registered. The mode on the panel is the cursor, so this stays right as
+    games start and end.
+
+    Args:
+        live_modes: The live modes, in registration order.
+        current_mode: The mode on the panel.
+        advance: True for the rotation's pick (the live mode after the one
+            showing). False for a peek (the one showing if it is still live,
+            else the first), which Vegas uses to ask whether anything is.
+    """
+    if not live_modes:
+        return None
+    if current_mode in live_modes:
+        if advance:
+            index = live_modes.index(current_mode)
+            return live_modes[(index + 1) % len(live_modes)]
+        return current_mode
+    return live_modes[0]
 
 
 def wifi_notice_preempts(notice: Optional[WifiNotice], on_demand_active: bool,

src/display_manager.py

@@ -317,6 +317,11 @@ class DisplayManager:
         # is handed to the writer; this only once it has been saved, so an
         # mtime touch never vouches for a frame still waiting to be written.
         self._saved_snapshot_digest: Optional[int] = None
+        # A changed frame reached _write_snapshot_if_due() inside the write
+        # interval and was skipped. Nothing writes it unless update_display()
+        # runs again, and a screen that draws once and holds never calls it
+        # again -- see write_owed_snapshot().
+        self._snapshot_owed = False
         self._snapshot_dir_prepared = False
         # Background writer used mid-scroll; see _write_snapshot_if_due.
         self._snapshot_cond = threading.Condition()
@@ -1788,9 +1793,10 @@ class DisplayManager:
 
             if frame_checksum is not None:
                 digest = frame_checksum
+                frame_changed = digest != self._last_snapshot_digest
                 action = snapshot_policy.decide(
                     now, self._last_snapshot_ts, self._last_snapshot_touch_ts,
-                    viewer_fresh, digest != self._last_snapshot_digest)
+                    viewer_fresh, frame_changed)
             else:
                 # Ask as if the frame had changed before paying to find out.
                 # decide() is monotone in frame_changed -- a SKIP for a
@@ -1802,22 +1808,36 @@ class DisplayManager:
                     now, self._last_snapshot_ts, self._last_snapshot_touch_ts,
                     viewer_fresh, True)
                 if action is snapshot_policy.SnapshotAction.SKIP:
+                    # Not hashed, so not known to be unchanged: owed until a
+                    # later look finds it written or unchanged.
+                    self._snapshot_owed = True
                     return
                 digest = zlib.adler32(self.image.tobytes())
-                if digest == self._last_snapshot_digest:
+                frame_changed = digest != self._last_snapshot_digest
+                if not frame_changed:
                     # Unchanged after all: the decision an unchanged frame gets.
                     action = snapshot_policy.decide(
                         now, self._last_snapshot_ts,
                         self._last_snapshot_touch_ts, viewer_fresh, False)
             if action is snapshot_policy.SnapshotAction.SKIP:
+                # A changed frame inside the write interval stays owed: the
+                # next update_display() would write it, but a static screen
+                # may not make one -- write_owed_snapshot() covers that.
+                self._snapshot_owed = frame_changed
                 return
             if (action is snapshot_policy.SnapshotAction.TOUCH
                     and self._saved_snapshot_digest == digest):
                 # mtime bump only: keeps the health check (snapshot age)
                 # green without paying for a PNG encode of an unchanged frame
+                # (this frame is already on disk, so nothing is owed).
+                self._snapshot_owed = False
                 os.utime(self._snapshot_path, None)
                 self._last_snapshot_touch_ts = now
                 return
+            # Owed until the write below succeeds: if it raises, the frame
+            # stays owed and write_owed_snapshot() retries it, rather than a
+            # held screen leaving the preview stale after one failed write.
+            self._snapshot_owed = True
             # (A TOUCH for a frame that isn't on disk yet -- still queued, or
             # its write failed -- is written instead: touching would make the
             # older file on disk look current.)
@@ -1842,9 +1862,39 @@ class DisplayManager:
             self._last_snapshot_ts = now
             self._last_snapshot_touch_ts = now
             self._last_snapshot_digest = digest
+            self._snapshot_owed = False
         except Exception as e:
             self._log_snapshot_failure(e)
 
+    def write_owed_snapshot(self) -> None:
+        """Write a frame the snapshot throttle skipped, once it is due.
+
+        The preview snapshot is only ever written from update_display(), and
+        at most once per write interval (snapshot_policy). A frame pushed
+        inside that interval is skipped, and is written by the next
+        update_display() that comes after it -- but a screen that draws its
+        card once and then holds it makes no further call. Its frame was on
+        the panel and never in the preview: soccer's recent/upcoming cards
+        skip redundant redraws, and the first one after an on-demand start
+        (pushed a few milliseconds after the controller's clear) left
+        /api/v3/display/current and the web preview black for the whole
+        screen while the panel showed the card.
+
+        The render loop calls this after each frame. Cheap when nothing is
+        owed (one attribute read); otherwise the usual policy decides, so
+        the write still waits out the interval and an unchanged frame is
+        never re-encoded.
+        """
+        if not self._snapshot_owed:
+            return
+        try:
+            if self._writes_suppressed():
+                return
+            with self._update_lock:
+                self._write_snapshot_if_due()
+        except Exception as e:  # pylint: disable=broad-except
+            self._log_snapshot_failure(e)
+
     def _log_snapshot_failure(self, error: Exception) -> None:
         # Snapshot failures must never break display — but they must not
         # be silent either: the snapshot's mtime is the web UI's display

src/error_aggregator.py

@@ -490,10 +490,13 @@ def record_error(
 # user reads, and the other way round for the clear request.
 #
 #   ERROR_SNAPSHOT_KEY       written by the display service only
-#   ERROR_CLEAR_REQUEST_KEY  written by the web interface only
+#   ERROR_CLEAR_REQUEST_KEY  written by the web interface only, as a fallback
 #
-# A clear is asynchronous: the web interface records a request, and the
-# display service applies it (clear_before) on its next tick and republishes.
+# A clear goes over the control socket (``errors.clear``): the display applies
+# it (clear_before) and republishes the snapshot before it answers. Only when
+# the socket cannot carry it (no socket, or a display older than the command)
+# does the web interface record a request in the mailbox, which the display
+# applies on its next tick; its tick reads that file only when it changed.
 # Until it has, the web interface hides whatever the snapshot shows from
 # before the cutoff, so a clear takes effect for readers immediately and a
 # snapshot published just before the request cannot bring old errors back.
@@ -598,13 +601,43 @@ class ErrorSnapshotPublisher:
         self._published_version: Optional[int] = None
         self._last_attempt: Optional[float] = None
         self._applied_clear_id: Optional[str] = None
+        # The widest cutoff applied in this process: a clear request at or
+        # before it has nothing left to clear (see _pending_cutoff).
+        self._applied_clear_cutoff: Optional[float] = None
+        from src.cache_manager import MailboxWatch  # the display's cache, loaded already
+        self._mailbox = MailboxWatch(ERROR_CLEAR_REQUEST_KEY)
         self._tick_lock = threading.Lock()
         self._stop = threading.Event()
         self._thread: Optional[threading.Thread] = None
 
+    def _clear(self, request_id: str, cutoff: float) -> int:
+        """Apply one clear and remember it. Caller holds _tick_lock."""
+        cleared = 0
+        if math.isfinite(cutoff):
+            cleared = self.aggregator.clear_before(datetime.fromtimestamp(cutoff))
+            _snapshot_logger.info("Cleared %d plugin error record(s) as requested (%s)",
+                                  cleared, request_id)
+            if self._applied_clear_cutoff is None or cutoff > self._applied_clear_cutoff:
+                self._applied_clear_cutoff = cutoff
+        # A malformed request is acknowledged too, so it is not retried forever.
+        self._applied_clear_id = request_id
+        return cleared
+
     def _apply_clear_request(self) -> bool:
-        """Honour a clear request we have not applied yet. True if one was."""
-        request = self.cache_manager.get(ERROR_CLEAR_REQUEST_KEY, max_age=None, memory_ttl=0)
+        """Honour a mailbox clear request we have not applied yet. True if one was.
+
+        The mailbox is the fallback for a web interface that could not use
+        the control socket (``errors.clear``, :meth:`clear_now`). It is read
+        only when its file changed since the last tick; otherwise a tick
+        costs one stat().
+        """
+        if not self._mailbox.changed(self.cache_manager):
+            return False
+        try:
+            request = self.cache_manager.get(ERROR_CLEAR_REQUEST_KEY, max_age=None, memory_ttl=0)
+        except Exception:
+            self._mailbox.forget()
+            raise
         if not isinstance(request, dict):
             return False
         request_id = request.get("request_id")
@@ -614,14 +647,30 @@ class ErrorSnapshotPublisher:
             cutoff = float(request.get("cutoff"))
         except (TypeError, ValueError):
             cutoff = float("nan")
-        if math.isfinite(cutoff):
-            cleared = self.aggregator.clear_before(datetime.fromtimestamp(cutoff))
-            _snapshot_logger.info("Cleared %d plugin error record(s) as requested (%s)",
-                                  cleared, request_id)
-        # A malformed request is acknowledged too, so it is not retried forever.
-        self._applied_clear_id = request_id
+        self._clear(request_id, cutoff)
         return True
 
+    def clear_now(self, request_id: str, cutoff: float) -> int:
+        """``errors.clear`` over the control socket: apply a clear at once and
+        republish the snapshot, so the web interface's next read has it.
+        Returns how many records were cleared. Raises when the snapshot
+        could not be written, so the caller is not told it worked."""
+        with self._tick_lock:
+            cleared = self._clear(request_id, float(cutoff))
+            self._publish(self.aggregator.version, self._clock())
+            return cleared
+
+    def _publish(self, version: int, now: float) -> None:
+        """Write the snapshot. Caller holds _tick_lock."""
+        # Stamp the attempt before writing: a cache that keeps failing
+        # is retried at the throttled rate, not on every tick.
+        self._last_attempt = now
+        snapshot = self.aggregator.build_snapshot()
+        snapshot["applied_clear_id"] = self._applied_clear_id
+        snapshot["applied_clear_cutoff"] = self._applied_clear_cutoff
+        self.cache_manager.set(ERROR_SNAPSHOT_KEY, snapshot)
+        self._published_version = version
+
     def tick(self) -> bool:
         """Apply a pending clear and publish if due. True if a snapshot was written."""
         with self._tick_lock:
@@ -635,13 +684,7 @@ class ErrorSnapshotPublisher:
                     if (self._last_attempt is not None
                             and now - self._last_attempt < self.min_interval):
                         return False
-                # Stamp the attempt before writing: a cache that keeps failing
-                # is retried at the throttled rate, not on every tick.
-                self._last_attempt = now
-                snapshot = self.aggregator.build_snapshot()
-                snapshot["applied_clear_id"] = self._applied_clear_id
-                self.cache_manager.set(ERROR_SNAPSHOT_KEY, snapshot)
-                self._published_version = version
+                self._publish(version, now)
                 return True
             except Exception as err:  # never let reporting break the display
                 _snapshot_logger.debug("Could not publish the plugin error snapshot: %s",
@@ -693,6 +736,22 @@ def start_error_snapshot_publisher(cache_manager: Any) -> Optional[ErrorSnapshot
         return None
 
 
+def apply_error_clear(request_id: str, args: Any) -> Dict[str, Any]:
+    """The display's handler for ``errors.clear`` on the control socket.
+
+    ``args`` is the contract's ErrorsClearArgs (``cutoff``, epoch seconds).
+    Runs on the socket's connection thread: the aggregator and the publisher
+    have their own locks, and nothing here touches rendering. Returns
+    ErrorsClearResult once the clear is applied and the snapshot rewritten.
+    """
+    publisher = _snapshot_publisher
+    if publisher is None:
+        raise RuntimeError("the error snapshot publisher is not running")
+    cutoff = float(args.cutoff)
+    cleared = publisher.clear_now(request_id, cutoff)
+    return {"request_id": request_id, "cutoff": cutoff, "cleared": cleared}
+
+
 # --- Reading side (web interface) -------------------------------------------
 
 def read_error_report(cache_manager: Any) -> Tuple[Optional[Dict[str, Any]], Optional[Dict[str, Any]]]:
@@ -731,7 +790,15 @@ def _pending_cutoff(snapshot: Optional[Dict[str, Any]],
         cutoff = float(clear_request.get("cutoff"))
     except (TypeError, ValueError):
         return None
-    return cutoff if math.isfinite(cutoff) else None
+    if not math.isfinite(cutoff):
+        return None
+    # A wider clear has been applied since (over the control socket): this
+    # older request has nothing left to hide.
+    applied = snapshot.get("applied_clear_cutoff") if snapshot is not None else None
+    if (isinstance(applied, (int, float)) and not isinstance(applied, bool)
+            and applied >= cutoff):
+        return None
+    return cutoff
 
 
 def _is_after(item: Any, field_name: str, cutoff: float) -> bool:
@@ -831,13 +898,31 @@ def _count_cleared(summary: Dict[str, Any], cutoff: float) -> Optional[int]:
     return None
 
 
-def request_error_clear(cache_manager: Any, cutoff: float) -> Dict[str, Any]:
+#: ``send(request_id, cutoff)`` hands a clear to the display over the control
+#: socket and returns its ErrorsClearResult, or None when the socket could
+#: not carry it and the mailbox should be written instead. Any exception it
+#: raises reaches the caller: the display had the request and failed it.
+ClearSender = Callable[[str, float], Optional[Dict[str, Any]]]
+
+
+def request_error_clear(cache_manager: Any, cutoff: float,
+                        send: Optional[ClearSender] = None) -> Dict[str, Any]:
     """Ask the display service to forget errors recorded at or before ``cutoff``.
 
-    Returns ``request_id``, ``cutoff`` (ISO, local time), ``cleared_count``
-    (see _count_cleared) and ``clear_requested``. Raises OSError when the
-    request did not reach the shared cache, since a cache without a usable
-    directory accepts set() and keeps nothing.
+    Over the control socket when ``send`` is given and carries it: the
+    display applies the clear and republishes its snapshot before it
+    answers, so nothing is written here. Otherwise (no socket, or a display
+    older than ``errors.clear``) a request is written to the
+    ``plugin_error_clear_request`` mailbox, which the display applies on
+    its next tick, and readers hide the cleared errors until then.
+
+    Returns ``request_id``, ``cutoff`` (ISO, local time), ``cleared_count``,
+    ``clear_requested``, ``applied`` (the display has already cleared them)
+    and ``transport`` (``socket`` or ``mailbox``). ``cleared_count`` is the
+    display's own count over the socket, else an estimate from the snapshot
+    (see _count_cleared). Raises OSError when a mailbox request did not reach
+    the shared cache, since a cache without a usable directory accepts set()
+    and keeps nothing.
 
     A request the display has not applied yet is only ever widened: a later,
     narrower one ("older than 24 hours" after "everything") overwriting it
@@ -848,8 +933,21 @@ def request_error_clear(cache_manager: Any, cutoff: float) -> Dict[str, Any]:
     if pending is not None:
         cutoff = max(cutoff, pending)
     before = error_summary_from_report(snapshot, clear_request)
+    request_id = uuid.uuid4().hex
+    answer = {
+        "clear_requested": True,
+        "request_id": request_id,
+        "cutoff": datetime.fromtimestamp(cutoff).isoformat(),
+    }
+    if send is not None:
+        result = send(request_id, cutoff)
+        if result is not None:
+            count = result.get("cleared")
+            return dict(answer, applied=True, transport="socket",
+                        cleared_count=count if isinstance(count, int) and not isinstance(count, bool)
+                        else _count_cleared(before, cutoff))
     request = {
-        "request_id": uuid.uuid4().hex,
+        "request_id": request_id,
         "cutoff": cutoff,
         "requested_at": time.time(),
     }
@@ -857,9 +955,5 @@ def request_error_clear(cache_manager: Any, cutoff: float) -> Dict[str, Any]:
     stored = cache_manager.get(ERROR_CLEAR_REQUEST_KEY, max_age=None, memory_ttl=0)
     if not isinstance(stored, dict) or stored.get("request_id") != request["request_id"]:
         raise OSError("the clear request was not stored in the shared cache")
-    return {
-        "cleared_count": _count_cleared(before, cutoff),
-        "clear_requested": True,
-        "request_id": request["request_id"],
-        "cutoff": datetime.fromtimestamp(cutoff).isoformat(),
-    }
+    return dict(answer, applied=False, transport="mailbox",
+                cleared_count=_count_cleared(before, cutoff))

src/font_manager.py

@@ -222,6 +222,39 @@ class FontManager:
             logger.error(f"Error registering fonts for plugin {plugin_id}: {e}", exc_info=True)
             return False
 
+    def forget_plugin_fonts(self, plugin_id: str) -> bool:
+        """Drop the fonts ``plugin_id``'s manifest registered: its manifest
+        and catalog, its ``plugin_id::family`` entries in font_catalog, and
+        cached font objects for those families. Called by core when a plugin
+        is unloaded, so a reload registers from its current manifest and a
+        removed plugin's fonts stop resolving.
+
+        FontManager takes no locks; like forget_manager_fonts this relies on
+        single dict operations being atomic and iterates snapshots, so a
+        render thread calling get_font() meanwhile cannot break it. Returns
+        True if the plugin had registered fonts.
+        """
+        prefix = f"{plugin_id}::"
+        manifest = self.plugin_fonts.pop(plugin_id, None)
+        catalog = self.plugin_font_catalogs.pop(plugin_id, None)
+        # Every namespaced entry, not just the families in the catalog: one
+        # whose file failed to load never made it into the catalog, and a
+        # caller may have added one directly.
+        for family in list(self.font_catalog):
+            if family.startswith(prefix):
+                self.font_catalog.pop(family, None)
+        # get_font() keys the cache f"{family}_{size_px}".
+        dropped = [key for key in list(self.font_cache) if key.startswith(prefix)]
+        for key in dropped:
+            self.font_cache.pop(key, None)
+        if dropped:
+            # Font objects someone may hold were dropped; see cache_generation.
+            self.cache_generation += 1
+        if manifest is None and catalog is None:
+            return False
+        logger.info("Forgot fonts of plugin %s", plugin_id)
+        return True
+
     def _validate_font_manifest(self, font_manifest: Dict[str, Any]) -> bool:
         """Validate the structure of a plugin's font manifest."""
         required_fields = ["fonts"]

src/ipc/client.py

@@ -3,8 +3,13 @@
 Every failure -- no socket (the display is stopped, or predates the socket),
 a refused or timed-out connection, a reply that breaks the contract, or an
 error the display returned -- raises :class:`ControlError` with a short
-``reason``, and the caller falls back to the file mailbox. Nothing here
-blocks for longer than ``timeout`` in total.
+``reason``. Nothing here blocks for longer than ``timeout`` in total.
+
+Whether the caller may then write the file mailbox instead is
+:func:`should_fall_back`: only when the display never took the request (it
+could not be reached, or it is too old to know the command). A display that
+took the request and then failed, refused or went quiet is answered as
+that, not posted a second time through the mailbox.
 """
 
 from __future__ import annotations
@@ -22,6 +27,7 @@ from src.ipc.contract import (
     SUBSCRIBE_KEEPALIVE_SECONDS,
     SUPPORTED_VERSIONS,
     Command,
+    ErrorCode,
     FrameReader,
     ProtocolError,
     Request,
@@ -49,17 +55,49 @@ class ControlError(Exception):
     ``refused``, ``timeout``, ``closed``, ``bad_response``, ``invalid_request``.
     When the display answered with an error, ``reason`` is that error's
     :class:`~src.ipc.contract.ErrorCode` (``busy``, ``unknown_command``, ...).
+
+    ``sent`` is True once the whole request was written to a connected
+    display, which may then have acted on it. A refusal the display sends
+    before it reads anything (``forbidden``, too many connections) carries
+    no request id and leaves ``sent`` False.
     """
 
-    def __init__(self, reason: str, message: str = ''):
+    def __init__(self, reason: str, message: str = '', *, sent: bool = False):
         super().__init__(reason, message)
         self.reason = reason
         self.message = message
+        self.sent = sent
 
     def __str__(self) -> str:
         return f'{self.reason}: {self.message}' if self.message else self.reason
 
 
+#: Answers from a display that read the request but does not speak it: one
+#: older than the command (an upgrade in progress) or the protocol version.
+#: It did nothing, so the mailbox is the way to reach it.
+UPGRADE_REASONS = frozenset({ErrorCode.UNKNOWN_COMMAND, ErrorCode.UNSUPPORTED_VERSION})
+
+
+def should_fall_back(error: BaseException) -> bool:
+    """May the caller write the file mailbox after ``error``?
+
+    Yes when the display never took the request: there is no socket (the
+    display is stopped, predates the socket, or it is switched off), the
+    connection was refused or timed out, the display turned the connection
+    away before reading it, or it is too old to know the command
+    (:data:`UPGRADE_REASONS`). Also for an error that is not a
+    :class:`ControlError` (a bug in the client), as before.
+
+    No once the display had the request: a ``busy`` queue, ``invalid_args``,
+    an ``internal`` error, or a timeout or hang-up after the request was
+    sent. The display may have applied it, or would refuse it from the
+    mailbox too, so a second copy there only hides the failure.
+    """
+    if not isinstance(error, ControlError):
+        return True
+    return not error.sent or error.reason in UPGRADE_REASONS
+
+
 def request(cmd: str, args: Optional[Mapping[str, Any]] = None, *,
             request_id: Optional[str] = None,
             timeout: float = DEFAULT_TIMEOUT_SECONDS,
@@ -93,11 +131,14 @@ def request(cmd: str, args: Optional[Mapping[str, Any]] = None, *,
     # A refusal before the request was read (forbidden, too many
     # connections) carries no id.
     if response.id != request_id and not (response.id is None and not response.ok):
-        raise ControlError('bad_response', 'the reply is for a different request')
+        raise ControlError('bad_response', 'the reply is for a different request', sent=True)
     if not response.ok:
         error = response.error
+        # No id: refused at the door (forbidden, too many connections),
+        # before the display read the request.
         raise ControlError(error.code if error else 'bad_response',
-                           error.message if error else '')
+                           error.message if error else '',
+                           sent=response.id is not None)
     return dict(response.result or {})
 
 
@@ -142,26 +183,31 @@ def _connect(paths: Sequence[str], deadline: float) -> socket.socket:
 
 
 def _exchange(sock: socket.socket, payload: bytes, deadline: float) -> Response:
+    """Send ``payload`` and read the reply. A failure once the whole request
+    is written raises with ``sent=True``: the display may have it."""
+    sent = False
     try:
         sock.settimeout(_remaining(deadline))
         sock.sendall(payload)
+        sent = True
         reader = FrameReader(MAX_MESSAGE_BYTES)
         while True:
             sock.settimeout(_remaining(deadline))
             data = sock.recv(4096)
             if not data:
-                raise ControlError('closed', 'the display closed the connection')
+                raise ControlError('closed', 'the display closed the connection', sent=sent)
             lines = reader.feed(data)
             if lines:
                 return Response.from_dict(decode_message(lines[0]))
     except socket.timeout:
-        raise ControlError('timeout', 'no reply in time') from None
+        raise ControlError('timeout', 'no reply in time', sent=sent) from None
     except ProtocolError as e:
-        raise ControlError('bad_response', e.message) from None
-    except ControlError:
+        raise ControlError('bad_response', e.message, sent=sent) from None
+    except ControlError as e:
+        e.sent = e.sent or sent
         raise
     except OSError as e:
-        raise ControlError('closed', str(e)) from None
+        raise ControlError('closed', str(e), sent=sent) from None
 
 
 # -- commands ---------------------------------------------------------------------------
@@ -227,6 +273,21 @@ def plugin_reload(plugin_id: str, *, timeout: Optional[float] = None,
                    else timeout, paths=paths)
 
 
+def errors_clear(request_id: str, cutoff: float, *,
+                 timeout: float = DEFAULT_TIMEOUT_SECONDS,
+                 paths: Optional[Sequence[str]] = None) -> Dict[str, Any]:
+    """Have the display forget the plugin errors recorded at or before
+    ``cutoff`` (epoch seconds) and publish its error snapshot again.
+
+    Returns :class:`~src.ipc.contract.ErrorsClearResult` once it is done.
+    Raises :class:`ControlError`: ``unknown_command`` from a display older
+    than the command, which still reads the ``plugin_error_clear_request``
+    mailbox.
+    """
+    return request(Command.ERRORS_CLEAR, {'cutoff': cutoff}, request_id=request_id,
+                   timeout=timeout, paths=paths)
+
+
 def ping(*, timeout: float = DEFAULT_TIMEOUT_SECONDS,
          paths: Optional[Sequence[str]] = None) -> Dict[str, Any]:
     return request(Command.PING, {}, timeout=timeout, paths=paths)

src/ipc/contract.py

@@ -149,12 +149,13 @@ class Command:
     PLUGIN_RELOAD = 'plugin.reload'
     STATE_GET = 'state.get'
     STATE_SUBSCRIBE = 'state.subscribe'
+    ERRORS_CLEAR = 'errors.clear'
 
 
 #: Every command version 1 defines, in the order ``hello`` reports them.
-#: ``brightness.set`` and ``plugin.reload`` came in stage 2, and ``state.get``
-#: and ``state.subscribe`` in stage 3, all within version 1 (see the module
-#: docstring on adding commands).
+#: ``brightness.set`` and ``plugin.reload`` came in stage 2, ``state.get``
+#: and ``state.subscribe`` in stage 3, and ``errors.clear`` in stage 4, all
+#: within version 1 (see the module docstring on adding commands).
 COMMANDS: Tuple[str, ...] = (
     Command.HELLO,
     Command.PING,
@@ -165,8 +166,15 @@ COMMANDS: Tuple[str, ...] = (
     Command.PLUGIN_RELOAD,
     Command.STATE_GET,
     Command.STATE_SUBSCRIBE,
+    Command.ERRORS_CLEAR,
 )
 
+#: Commands the connection thread answers itself, through a handler the
+#: display registers (``ControlServer(handlers=...)``), because they touch
+#: nothing the render thread owns. A display that registered none answers
+#: ``unknown_command``, and the client falls back as from an older display.
+DIRECT_COMMANDS = frozenset({Command.ERRORS_CLEAR})
+
 #: Commands that are queued for the render thread.
 QUEUED_COMMANDS = frozenset({Command.ON_DEMAND_START, Command.ON_DEMAND_STOP,
                              Command.BRIGHTNESS_SET, Command.PLUGIN_RELOAD})
@@ -565,8 +573,32 @@ class StateSubscribeArgs:
         return cls()
 
 
+@dataclass(frozen=True)
+class ErrorsClearArgs:
+    """``errors.clear``: forget the plugin errors recorded at or before
+    ``cutoff`` (seconds since the epoch), as ``POST /api/v3/errors/clear``
+    asks. The request id is the clear's id, which the display's error
+    snapshot then reports as ``applied_clear_id``.
+    """
+    cutoff: float
+
+    def to_dict(self) -> Dict[str, Any]:
+        return {'cutoff': self.cutoff}
+
+    @classmethod
+    def from_dict(cls, args: Mapping[str, Any]) -> 'ErrorsClearArgs':
+        value = args.get('cutoff')
+        if isinstance(value, bool) or not isinstance(value, (int, float)):
+            raise ProtocolError(ErrorCode.INVALID_ARGS, 'cutoff must be a number of seconds')
+        if not math.isfinite(value) or value < 0:
+            raise ProtocolError(ErrorCode.INVALID_ARGS,
+                                'cutoff must be a finite, non-negative number of seconds')
+        return cls(cutoff=float(value))
+
+
 CommandArgs = Union[HelloArgs, OnDemandStartArgs, OnDemandStopArgs, NoArgs,
-                    BrightnessSetArgs, PluginReloadArgs, StateGetArgs, StateSubscribeArgs]
+                    BrightnessSetArgs, PluginReloadArgs, StateGetArgs, StateSubscribeArgs,
+                    ErrorsClearArgs]
 
 #: The arguments of a command that goes on the render thread's queue.
 QueuedArgs = Union[OnDemandStartArgs, OnDemandStopArgs, BrightnessSetArgs, PluginReloadArgs]
@@ -581,6 +613,7 @@ _ARG_TYPES: Dict[str, Any] = {
     Command.PLUGIN_RELOAD: PluginReloadArgs,
     Command.STATE_GET: StateGetArgs,
     Command.STATE_SUBSCRIBE: StateSubscribeArgs,
+    Command.ERRORS_CLEAR: ErrorsClearArgs,
 }
 
 
@@ -653,6 +686,13 @@ class PluginReloadResult(TypedDict):
     modes: List[str]
 
 
+class ErrorsClearResult(TypedDict):
+    """``errors.clear``, once applied and the error snapshot republished."""
+    request_id: str
+    cutoff: float
+    cleared: int
+
+
 class LoopState(TypedDict):
     """``loop``: is the render loop still going round?
 

src/ipc/server.py

@@ -6,7 +6,9 @@ rendering: a command that changes the panel is validated, put on a bounded
 queue and acknowledged, and the render thread drains that queue at the point
 where it reads the file mailbox (``DisplayController._poll_on_demand_requests``),
 handing each command to the same code. Queries (``on_demand.status``) are
-answered from a snapshot callable the display provides.
+answered from a snapshot callable the display provides, and the few commands
+that touch nothing the render thread owns (``errors.clear``) by a handler the
+display registers, on the connection thread.
 
 The queue also wakes the render thread: :meth:`ControlServer.wait_for_command`
 is what it waits on in place of a sleep, so a command lands within a frame on
@@ -62,6 +64,7 @@ from src.ipc.contract import (
     AWAITED_COMMANDS,
     COMMANDS,
     DEFAULT_SOCKET_DIR,
+    DIRECT_COMMANDS,
     DEFAULT_SOCKET_PATH,
     MAX_MESSAGE_BYTES,
     MAX_SUBSCRIBERS,
@@ -107,7 +110,8 @@ MAX_CLIENTS = 8
 
 #: Commands waiting for the render thread. It drains them at least every
 #: 0.25 s, so a full queue means the render thread is stuck, and the client
-#: is told ``busy`` (and falls back to the mailbox) instead of piling up work.
+#: is told ``busy`` instead of piling up work. The mailbox would not be read
+#: either, so the web interface reports the failure rather than fall back.
 QUEUE_SIZE = 16
 
 #: Timeout for one recv()/send() on a connection.
@@ -552,6 +556,12 @@ def server_socket_path(environ: Optional[Mapping[str, str]] = None) -> Optional[
 
 StatusProvider = Callable[[], Dict[str, Any]]
 
+#: A handler for one of DIRECT_COMMANDS, ``(request_id, args) -> result``. It
+#: runs on the connection thread, so it must not touch what the render thread
+#: owns. It may raise ProtocolError to answer with that error's code; any
+#: other exception is answered ``internal``.
+DirectHandler = Callable[[str, Any], Mapping[str, Any]]
+
 
 class ControlServer:
     """Serves the control socket on background threads.
@@ -569,9 +579,12 @@ class ControlServer:
                  await_seconds: Optional[Mapping[str, float]] = None,
                  state_hub: Optional[StateHub] = None,
                  max_subscribers: int = MAX_SUBSCRIBERS,
-                 keepalive: float = SUBSCRIBE_KEEPALIVE_SECONDS):
+                 keepalive: float = SUBSCRIBE_KEEPALIVE_SECONDS,
+                 handlers: Optional[Mapping[str, DirectHandler]] = None):
         self.path = path
         self.state_hub = state_hub
+        self._handlers: Dict[str, DirectHandler] = {
+            cmd: fn for cmd, fn in (handlers or {}).items() if cmd in DIRECT_COMMANDS}
         self._subscriber_slots = threading.BoundedSemaphore(max_subscribers)
         self._keepalive = keepalive
         self._await_seconds: Dict[str, float] = dict(AWAIT_SECONDS)
@@ -759,8 +772,22 @@ class ControlServer:
         """
         return self._pending.wait(timeout)
 
+    def wake(self) -> None:
+        """Wake the render thread as a queued command would, with nothing queued.
+
+        For work that reaches the display another way in the same process (a
+        plugin's on-demand request, ``DisplayController.submit_plugin_on_demand``):
+        the render thread returns from :meth:`wait_for_command` and drains,
+        and reads the caller's own queue there. Safe from any thread.
+        """
+        self._pending.set()
+
     def drain(self) -> List[QueuedCommand]:
-        """Every queued command, oldest first. Called from the render thread."""
+        """Every queued command, oldest first. Called from the render thread.
+
+        Clears the wake flag first, so anything queued (or woken for) while
+        this runs wakes the next wait again.
+        """
         commands: List[QueuedCommand] = []
         self._pending.clear()
         while True:
@@ -1028,6 +1055,9 @@ class ControlServer:
                 snap = hub.snapshot()
             return Response.success(request.id, fit_snapshot(snap), v=request.v)
 
+        if request.cmd in DIRECT_COMMANDS:
+            return self._direct(request, args)
+
         if request.cmd in QUEUED_COMMANDS and isinstance(args, (
                 OnDemandStartArgs, OnDemandStopArgs, BrightnessSetArgs, PluginReloadArgs)):
             awaited = request.cmd in AWAITED_COMMANDS
@@ -1055,6 +1085,25 @@ class ControlServer:
         return Response.failure(request.id, ErrorCode.INTERNAL,
                                 f'{request.cmd} is not implemented', v=request.v)
 
+    def _direct(self, request: Request, args: Any) -> Response:
+        """A command the display answers on this thread (DIRECT_COMMANDS)."""
+        handler = self._handlers.get(request.cmd)
+        if handler is None:
+            # Answered as an older display would, so the client falls back.
+            return Response.failure(request.id, ErrorCode.UNKNOWN_COMMAND,
+                                    f'{request.cmd} is not served by this display',
+                                    v=request.v)
+        try:
+            result = handler(request.id, args)
+        except ProtocolError as e:
+            return Response.failure(request.id, e.code, e.message, v=request.v)
+        except Exception:  # pylint: disable=broad-except
+            logger.exception("Control socket: %s %s failed", request.cmd, request.id)
+            return Response.failure(request.id, ErrorCode.INTERNAL,
+                                    'the display failed to apply it', v=request.v)
+        logger.info("Control socket applied %s %s", request.cmd, request.id)
+        return Response.success(request.id, dict(result), v=request.v)
+
     def _await_outcome(self, request: Request, outcome: CommandOutcome) -> Response:
         """Answer an awaited command once the render thread has applied it.
 
@@ -1079,7 +1128,9 @@ class ControlServer:
 def start_control_server(status_provider: Optional[StatusProvider] = None,
                          cache_dir: Optional[str] = None,
                          environ: Optional[Mapping[str, str]] = None,
-                         state_hub: Optional[StateHub] = None) -> Optional[ControlServer]:
+                         state_hub: Optional[StateHub] = None,
+                         handlers: Optional[Mapping[str, DirectHandler]] = None,
+                         ) -> Optional[ControlServer]:
     """Start the display's control socket, or return None when it can't run.
 
     None covers Windows, ``LEDMATRIX_CONTROL_SOCKET=off`` and any failure to
@@ -1091,7 +1142,7 @@ def start_control_server(status_provider: Optional[StatusProvider] = None,
         logger.debug("Control socket disabled or unsupported here; using the file mailbox only")
         return None
     server = ControlServer(path, status_provider, resolve_socket_group(cache_dir),
-                           state_hub=state_hub)
+                           state_hub=state_hub, handlers=handlers)
     return server if server.start() else None
 
 

src/malloc_tuning.py

@@ -0,0 +1,123 @@
+"""Keep glibc's malloc from holding on to memory the display has freed.
+
+The display process allocates and frees PIL images and numpy buffers all day
+from a dozen threads. glibc gives each allocating thread its own malloc arena
+(up to 8 x CPU count) and returns little of what is freed inside them to the
+OS, so resident memory climbs for hours while the live data stays flat. Two
+in-process remedies, both standard library only (ctypes) and both no-ops off
+Linux/glibc:
+
+* :func:`cap_arenas` -- ``mallopt(M_ARENA_MAX, 2)``, the in-process twin of the
+  unit's ``Environment=MALLOC_ARENA_MAX=2``. Units installed before that line
+  existed never got it (systemd runs the copy in /etc/systemd/system), so the
+  process applies it itself. Call it before any other thread starts: arenas
+  already created stay. A ``MALLOC_ARENA_MAX`` set in the environment wins.
+* :class:`MallocTrimmer` -- ``malloc_trim(0)`` at most every few minutes,
+  called from the render loop between screens, where no frame is being drawn.
+  glibc 2.8+ releases free pages from the middle of every arena, not only the
+  top of the main heap.
+
+Without glibc (macOS, Windows, musl, the dev server on any of them) nothing is
+loaded and every call returns False.
+"""
+import ctypes
+import logging
+import os
+import sys
+import time
+from typing import Any, Callable, Optional
+
+logger = logging.getLogger(__name__)
+
+#: glibc's mallopt() parameter number for the arena cap (malloc.h).
+M_ARENA_MAX = -8
+
+#: The arena cap applied when the environment does not set one; the same value
+#: as the unit's ``MALLOC_ARENA_MAX``.
+DEFAULT_ARENA_MAX = 2
+
+#: Seconds between malloc_trim() calls. A trim takes about 1-20 ms on a Pi 4,
+#: so this keeps it far from frame timing while still returning memory long
+#: before it piles up.
+TRIM_INTERVAL_SECONDS = 300.0
+
+_UNLOADED = object()
+_libc: Any = _UNLOADED
+
+
+def _load_libc() -> Optional[Any]:
+    """The process's C library if it is glibc with malloc_trim, else None."""
+    global _libc
+    if _libc is _UNLOADED:
+        _libc = None
+        if sys.platform.startswith('linux'):
+            try:
+                libc = ctypes.CDLL(None)
+                # gnu_get_libc_version is glibc-only, so musl (which has
+                # mallopt but no malloc_trim) is left alone as a whole.
+                if all(hasattr(libc, name) for name in
+                       ('gnu_get_libc_version', 'malloc_trim', 'mallopt')):
+                    libc.malloc_trim.argtypes = [ctypes.c_size_t]
+                    libc.malloc_trim.restype = ctypes.c_int
+                    libc.mallopt.argtypes = [ctypes.c_int, ctypes.c_int]
+                    libc.mallopt.restype = ctypes.c_int
+                    _libc = libc
+            except (OSError, AttributeError, TypeError):
+                logger.debug("glibc malloc controls unavailable", exc_info=True)
+    return _libc
+
+
+def cap_arenas(max_arenas: int = DEFAULT_ARENA_MAX) -> bool:
+    """Cap glibc's malloc arenas at ``max_arenas``. True when the cap was set.
+
+    Skipped when ``MALLOC_ARENA_MAX`` is in the environment: glibc has read it
+    already, and an operator who set it chose that value.
+    """
+    if os.environ.get('MALLOC_ARENA_MAX'):
+        return False
+    libc = _load_libc()
+    if libc is None:
+        return False
+    try:
+        return bool(libc.mallopt(M_ARENA_MAX, int(max_arenas)))
+    except Exception:  # pylint: disable=broad-except
+        logger.debug("mallopt(M_ARENA_MAX) failed", exc_info=True)
+        return False
+
+
+class MallocTrimmer:
+    """Calls ``malloc_trim(0)`` at most once per ``interval`` seconds.
+
+    :meth:`maybe_trim` is meant for an idle point of the render loop; it costs
+    one clock read when no trim is due. The first trim comes one interval
+    after construction, so start-up's allocations have settled.
+    """
+
+    def __init__(self, interval: float = TRIM_INTERVAL_SECONDS,
+                 clock: Callable[[], float] = time.monotonic) -> None:
+        self._interval = interval
+        self._clock = clock
+        self._libc = _load_libc()
+        self._next = clock() + interval
+
+    @property
+    def available(self) -> bool:
+        return self._libc is not None
+
+    def maybe_trim(self) -> bool:
+        """Trim if one is due. True when malloc_trim ran and released memory."""
+        if self._libc is None:
+            return False
+        now = self._clock()
+        if now < self._next:
+            return False
+        self._next = now + self._interval
+        try:
+            released = bool(self._libc.malloc_trim(0))
+        except Exception:  # pylint: disable=broad-except
+            logger.debug("malloc_trim failed; not trying again", exc_info=True)
+            self._libc = None
+            return False
+        logger.debug("malloc_trim(0) took %.1f ms, released=%s",
+                     (self._clock() - now) * 1000.0, released)
+        return released

src/plugin_system/base_plugin.py

@@ -11,7 +11,6 @@ Stability: Stable - maintains backward compatibility
 from abc import ABC, abstractmethod
 from enum import Enum
 from typing import Dict, Any, Optional, List
-import math
 import os
 import sys
 from src.deprecation import deprecated, warn_deprecated
@@ -241,26 +240,6 @@ def resolve_vegas_participation(plugin: Any, plugin_id: Optional[str] = None) ->
     return legacy_vegas_participation(plugin)
 
 
-def finite_seconds(value: Any) -> Optional[float]:
-    """``value`` as seconds when it is a finite number or a numeric string,
-    else None. A bool is not a number here, though it is an int: True would
-    read as a one-second screen.
-
-    How the core reads a plugin's get_display_duration() -- the rotation
-    (DisplayController._get_display_duration) and the Vegas static pause --
-    which several plugins answer straight from config.json, so a value saved
-    as "20" or null arrives as a string or None. A number at or below zero is
-    returned as it is; each caller has its own rule for that.
-    """
-    if isinstance(value, bool):
-        return None
-    try:
-        seconds = float(value)
-    except (TypeError, ValueError, OverflowError):
-        return None
-    return seconds if math.isfinite(seconds) else None
-
-
 class BasePlugin(ABC):
     """
     Base class that all plugins must inherit from.
@@ -1091,6 +1070,65 @@ class BasePlugin(ABC):
         if callable(notify):
             notify(self.plugin_id)
 
+    def request_on_demand(self, mode: Optional[str] = None,
+                          duration: Optional[float] = None,
+                          pinned: bool = False) -> Optional[str]:
+        """
+        Take the screen now: show this plugin on demand. Safe from any thread.
+
+        For a plugin that reacts to something outside the rotation -- an MQTT
+        message, a timer, a detection -- and wants the panel for it. The
+        request goes straight to the display in this process and is applied
+        on its render thread within a frame or so, exactly like an on-demand
+        start from the web interface.
+
+        Args:
+            mode: One of this plugin's display modes; None for its first.
+            duration: Seconds to show it before the rotation resumes; None
+                (or zero) for no limit, until end_on_demand() or the user
+                stops it.
+            pinned: Stay on ``mode`` instead of cycling through the
+                plugin's other modes.
+
+        Returns:
+            The request id once the display has queued it, or None when
+            there is no display in this process to ask (the web interface,
+            scripts/check_plugin.py) or its queue is full. A plugin that
+            also runs on cores without this method writes the
+            ``display_on_demand_request`` mailbox on None, as before; see
+            "On-demand display" in docs/PLUGIN_API_REFERENCE.md.
+
+        Example::
+
+            if not (hasattr(self, 'request_on_demand')
+                    and self.request_on_demand(mode='my_alert', duration=15)):
+                self._write_on_demand_mailbox(...)   # older cores
+        """
+        request = getattr(getattr(self, 'plugin_manager', None), 'request_on_demand', None)
+        if not callable(request):
+            return None
+        request_id = request(self.plugin_id, mode=mode, duration=duration, pinned=pinned)
+        # Only a real id counts: a test's MagicMock manager answers a mock,
+        # which must read as "not taken" so the plugin's fallback runs.
+        return request_id if isinstance(request_id, str) else None
+
+    def end_on_demand(self) -> Optional[str]:
+        """
+        Give the screen back: end this plugin's on-demand session. Any thread.
+
+        Ends only a session this plugin owns. One the user started for
+        another plugin, or a session that already ended, is left alone. The
+        rotation resumes where it left off.
+
+        Returns:
+            The request id once queued, or None as request_on_demand() does.
+        """
+        end = getattr(getattr(self, 'plugin_manager', None), 'end_on_demand', None)
+        if not callable(end):
+            return None
+        request_id = end(self.plugin_id)
+        return request_id if isinstance(request_id, str) else None
+
     def get_vegas_participation(self) -> str:
         """
         How this plugin takes part in Vegas mode: ``'scroll'``, ``'pause'`` or

src/plugin_system/plugin_local_files.py

@@ -0,0 +1,204 @@
+"""
+Files a plugin writes beside itself at runtime, which an update must keep.
+
+A store update replaces a plugin's directory with a fresh download and then
+deletes the old copy. Anything the plugin created there -- OAuth tokens, a
+client-secrets file, a PKCE verifier, cached state -- is in no release, so the
+fresh download does not contain it and deleting the old copy destroys it. On
+2026-10-04 updating calendar 1.2.9 -> 1.2.12 that way deleted its
+``token.pickle`` and ``credentials.json``, and the calendar stopped until they
+were restored from a backup.
+
+What counts as "the plugin's own local file" is the union of:
+
+* :data:`KNOWN_STATE_PATTERNS` -- secret and state files plugins are known to
+  write, kept even when a plugin forgot to gitignore them; and
+* whatever the plugin's own ``.gitignore`` (old copy or new) excludes. A file
+  the author ignores is by definition not part of a release.
+
+A file the new release ships is never overwritten: tracked content wins. Byte
+code (``__pycache__``, ``*.pyc``) and ``.git`` are never carried, since they
+belong to the old code rather than to the user.
+"""
+
+from __future__ import annotations
+
+import fnmatch
+import os
+import re
+import shutil
+from pathlib import Path
+from typing import Iterable, List, Optional, Pattern, Tuple
+
+__all__ = [
+    'KNOWN_STATE_PATTERNS',
+    'carry_over_local_files',
+    'is_known_state_file',
+    'local_files_to_keep',
+]
+
+# Basename globs. Kept even when the plugin's .gitignore does not list them.
+KNOWN_STATE_PATTERNS: Tuple[str, ...] = (
+    'token.pickle',
+    '*.pickle',
+    'token.json',
+    'credentials.json',
+    'config_secrets.json',
+    '.pkce_code_verifier',
+)
+
+_NEVER_CARRY_DIRS = frozenset({'.git', '__pycache__'})
+_NEVER_CARRY_SUFFIXES = ('.pyc', '.pyo')
+
+
+def is_known_state_file(rel_path: str) -> bool:
+    """True when ``rel_path``'s basename is a known secret/state file."""
+    name = rel_path.replace('\\', '/').rsplit('/', 1)[-1]
+    return any(fnmatch.fnmatchcase(name, p) for p in KNOWN_STATE_PATTERNS)
+
+
+class _GitIgnore:
+    """The subset of gitignore semantics plugin .gitignore files use.
+
+    Supports comments, ``!`` negation (last match wins), a trailing ``/`` for
+    directory-only patterns, anchoring by a leading or embedded ``/``, ``*``,
+    ``?``, ``[...]`` and ``**``. As in git, a file under an ignored directory
+    is ignored regardless of later negations.
+    """
+
+    def __init__(self, lines: Iterable[str]):
+        self._rules: List[Tuple[Pattern[str], bool, bool]] = []
+        for raw in lines:
+            line = raw.rstrip('\n').rstrip()
+            if not line or line.startswith('#'):
+                continue
+            negate = line.startswith('!')
+            if negate:
+                line = line[1:]
+            elif line.startswith('\\'):
+                line = line[1:]
+            dir_only = line.endswith('/')
+            line = line.rstrip('/')
+            if not line:
+                continue
+            anchored = '/' in line
+            line = line.lstrip('/')
+            body = self._translate(line)
+            regex = body if anchored else r'(?:.*/)?' + body
+            self._rules.append((re.compile(r'\A' + regex + r'\Z'), negate, dir_only))
+
+    @staticmethod
+    def _translate(pattern: str) -> str:
+        out, i, n = [], 0, len(pattern)
+        while i < n:
+            if pattern.startswith('**/', i):
+                out.append(r'(?:.*/)?')
+                i += 3
+            elif pattern.startswith('/**', i) and i + 3 == n:
+                out.append(r'/.*')
+                i += 3
+            elif pattern.startswith('**', i):
+                out.append(r'.*')
+                i += 2
+            elif pattern[i] == '*':
+                out.append(r'[^/]*')
+                i += 1
+            elif pattern[i] == '?':
+                out.append(r'[^/]')
+                i += 1
+            elif pattern[i] == '[':
+                end = pattern.find(']', i + 1)
+                if end == -1:
+                    out.append(re.escape('['))
+                    i += 1
+                else:
+                    cls = pattern[i + 1:end]
+                    if cls.startswith('!'):
+                        cls = '^' + cls[1:]
+                    out.append('[' + cls.replace('\\', '\\\\') + ']')
+                    i = end + 1
+            else:
+                out.append(re.escape(pattern[i]))
+                i += 1
+        return ''.join(out)
+
+    def _decide(self, rel: str, is_dir: bool) -> Optional[bool]:
+        verdict = None
+        for regex, negate, dir_only in self._rules:
+            if dir_only and not is_dir:
+                continue
+            if regex.match(rel):
+                verdict = not negate
+        return verdict
+
+    def ignores(self, rel_path: str) -> bool:
+        if not self._rules:
+            return False
+        parts = rel_path.replace('\\', '/').split('/')
+        for depth in range(1, len(parts)):
+            if self._decide('/'.join(parts[:depth]), True):
+                return True
+        return bool(self._decide('/'.join(parts), False))
+
+
+def _read_gitignore(plugin_dir: Path) -> List[str]:
+    try:
+        return (plugin_dir / '.gitignore').read_text(
+            encoding='utf-8', errors='replace').splitlines()
+    except OSError:
+        return []
+
+
+def local_files_to_keep(old_dir: Path, new_dir: Path) -> List[str]:
+    """Relative paths (``/``-separated) in ``old_dir`` to copy into ``new_dir``.
+
+    Regular files only; symlinks and anything the new release already ships
+    are skipped.
+    """
+    old_dir, new_dir = Path(old_dir), Path(new_dir)
+    ignore = _GitIgnore(_read_gitignore(old_dir) + _read_gitignore(new_dir))
+    keep: List[str] = []
+    for root, dirs, files in os.walk(old_dir):
+        dirs[:] = sorted(d for d in dirs if d not in _NEVER_CARRY_DIRS
+                         and not os.path.islink(os.path.join(root, d)))
+        rel_root = os.path.relpath(root, old_dir)
+        for name in sorted(files):
+            if name.endswith(_NEVER_CARRY_SUFFIXES):
+                continue
+            full = os.path.join(root, name)
+            if os.path.islink(full) or not os.path.isfile(full):
+                continue
+            rel = name if rel_root == '.' else f"{rel_root}/{name}".replace('\\', '/')
+            if not (is_known_state_file(rel) or ignore.ignores(rel)):
+                continue
+            if os.path.lexists(new_dir / rel):
+                continue
+            keep.append(rel)
+    return keep
+
+
+def carry_over_local_files(
+    old_dir: Path, new_dir: Path
+) -> Tuple[List[str], List[Tuple[str, str]]]:
+    """Copy the plugin's local files from ``old_dir`` into ``new_dir``.
+
+    Copies rather than moves, so ``old_dir`` stays a complete copy until the
+    caller deletes it. Returns ``(copied, failed)`` where ``failed`` pairs a
+    relative path with the error; the caller should keep ``old_dir`` when
+    anything failed.
+    """
+    copied: List[str] = []
+    failed: List[Tuple[str, str]] = []
+    try:
+        candidates = local_files_to_keep(old_dir, new_dir)
+    except OSError as e:
+        return copied, [('.', str(e))]
+    for rel in candidates:
+        dest = Path(new_dir) / rel
+        try:
+            dest.parent.mkdir(parents=True, exist_ok=True)
+            shutil.copy2(Path(old_dir) / rel, dest)
+            copied.append(rel)
+        except OSError as e:
+            failed.append((rel, str(e)))
+    return copied, failed

src/plugin_system/plugin_manager.py

@@ -15,6 +15,7 @@ import sys
 import time
 import threading
 import types
+import uuid
 from pathlib import Path
 from typing import Callable, Dict, List, NamedTuple, Optional, Any, Tuple, Union
 import logging
@@ -214,6 +215,9 @@ class PluginManager:
         # add_update_listener(). A tuple, replaced rather than mutated, so the
         # worker can iterate it without a lock.
         self._update_listeners: Tuple[Callable[[str], None], ...] = ()
+        # Where plugins' on-demand requests go: the display controller's
+        # submit_plugin_on_demand. See set_on_demand_handler().
+        self._on_demand_handler: Optional[Callable[[Dict[str, Any]], bool]] = None
         # Config changes that found the plugin's lock busy, latest per plugin,
         # with the instance they were meant for. See apply_config_change().
         self._deferred_config_changes: Dict[str, Tuple[Any, Dict[str, Any]]] = {}
@@ -597,11 +601,21 @@ class PluginManager:
             self.plugin_loader.unregister_plugin_modules(plugin_id)
         except Exception as e:  # pragma: no cover - defensive
             self.logger.debug("Could not drop modules of %s: %s", plugin_id, e)
-        try:
-            if self.font_manager is not None and hasattr(self.font_manager, 'forget_manager_fonts'):
-                self.font_manager.forget_manager_fonts(plugin_id)
-        except Exception as e:
-            self.logger.debug("Could not forget fonts of %s: %s", plugin_id, e)
+        self._forget_plugin_fonts(plugin_id)
+
+    def _forget_plugin_fonts(self, plugin_id: str) -> None:
+        """Drop what the FontManager holds for a plugin: the fonts its
+        instance reported using (the Fonts tab's "Used by") and the fonts its
+        manifest registered. Never raises."""
+        if self.font_manager is None:
+            return
+        for name in ('forget_manager_fonts', 'forget_plugin_fonts'):
+            if not hasattr(self.font_manager, name):
+                continue
+            try:
+                getattr(self.font_manager, name)(plugin_id)
+            except Exception as e:
+                self.logger.debug("Could not forget fonts of %s (%s): %s", plugin_id, name, e)
     
     #: Config keys the **core** reads out of a plugin's own config block. The
     #: plugin never declares them, so a schema with
@@ -846,12 +860,9 @@ class PluginManager:
             # Delegate sub-module and cached-module cleanup to the loader
             self.plugin_loader.unregister_plugin_modules(plugin_id)
 
-            # Its font registrations go with it (the Fonts tab's "Used by").
-            try:
-                if self.font_manager is not None and hasattr(self.font_manager, 'forget_manager_fonts'):
-                    self.font_manager.forget_manager_fonts(plugin_id)
-            except Exception as e:
-                self.logger.debug("Could not forget fonts of %s: %s", plugin_id, e)
+            # Its font registrations go with it: the fonts it reported using
+            # and the ones its manifest registered.
+            self._forget_plugin_fonts(plugin_id)
 
             # Update state
             self.state_manager.set_state(plugin_id, PluginState.UNLOADED)
@@ -1844,3 +1855,73 @@ class PluginManager:
             done = sorted(self._completed_updates)
             self._completed_updates.clear()
             return done
+
+    # -- on-demand requests from plugins -------------------------------------
+
+    def set_on_demand_handler(
+            self, handler: Optional[Callable[[Dict[str, Any]], bool]]) -> None:
+        """Route plugins' on-demand requests to ``handler`` (None: nowhere).
+
+        The display controller sets its ``submit_plugin_on_demand`` here
+        before any plugin loads. The handler takes a mailbox-shaped request
+        from any thread, queues it for the render thread and returns True,
+        or False when it could not. A plugin manager with no handler (the
+        web interface's, a test's, scripts/check_plugin.py's) has no screen
+        to give, so request_on_demand() there answers None.
+        """
+        self._on_demand_handler = handler
+
+    def request_on_demand(self, plugin_id: str, mode: Optional[str] = None,
+                          duration: Optional[float] = None,
+                          pinned: bool = False) -> Optional[str]:
+        """Ask the display to show ``plugin_id`` now. Safe from any thread.
+
+        BasePlugin.request_on_demand() lands here; see it for the arguments.
+        Returns the request id once the display has queued the request (it
+        is applied on the render thread within a frame or so), or None when
+        this process has no display to ask or its queue is full.
+        """
+        if not isinstance(plugin_id, str) or not plugin_id:
+            raise ValueError('plugin_id is required')
+        if mode is not None and (not isinstance(mode, str) or not mode):
+            raise ValueError('mode must be a non-empty string or None')
+        if duration is not None:
+            if isinstance(duration, bool) or not isinstance(duration, (int, float)):
+                raise ValueError('duration must be a number of seconds or None')
+            if not math.isfinite(duration) or duration <= 0:
+                duration = None   # the display reads these as "no limit" too
+            else:
+                duration = float(duration)
+        return self._submit_on_demand({
+            'action': 'start', 'plugin_id': plugin_id, 'mode': mode,
+            'duration': duration, 'pinned': bool(pinned)})
+
+    def end_on_demand(self, plugin_id: str) -> Optional[str]:
+        """Give the screen back, if ``plugin_id``'s on-demand session has it.
+
+        BasePlugin.end_on_demand() lands here. A session the plugin does not
+        own (the user started another plugin from the web interface, say) is
+        left alone. Returns the request id once queued, or None as
+        request_on_demand() does.
+        """
+        if not isinstance(plugin_id, str) or not plugin_id:
+            raise ValueError('plugin_id is required')
+        return self._submit_on_demand({'action': 'stop', 'plugin_id': plugin_id})
+
+    def _submit_on_demand(self, request: Dict[str, Any]) -> Optional[str]:
+        # __dict__.get: tests build bare managers with PluginManager.__new__.
+        handler = self.__dict__.get('_on_demand_handler')
+        if handler is None:
+            return None
+        request_id = str(uuid.uuid4())
+        request.update({'request_id': request_id, 'timestamp': time.time(),
+                        'source': 'plugin'})
+        try:
+            accepted = handler(request)
+        except Exception as exc:  # pylint: disable=broad-except
+            self._warn_rate_limited(
+                "on-demand-handler",
+                "The on-demand request from plugin %s failed: %r",
+                request.get('plugin_id'), exc)
+            return None
+        return request_id if accepted else None

src/plugin_system/store_install.py

@@ -22,6 +22,7 @@ from src.plugin_system.plugin_loader import (
     contained_plugin_dir, requirements_to_install,
 )
 from src.plugin_system.plugin_dirs import BACKUP_MARKER
+from src.plugin_system.plugin_local_files import carry_over_local_files
 from src.plugin_system.repo_urls import (
     USER_AGENT, github_api_headers, github_owner_repo, normalize_repo_url,
 )
@@ -92,7 +93,9 @@ class _InstallMixin:
                 raise
 
             if installed:
-                self._discard_backup(plugin_id, backup_path, "install")
+                self._discard_backup(
+                    plugin_id, backup_path, "install",
+                    new_path=self._existing_install(plugin_id) or plugin_path)
                 return True
 
             self._restore_backup(plugin_id, plugin_path, backup_path, "Install")
@@ -133,8 +136,33 @@ class _InstallMixin:
             return f"could not set aside {plugin_path}: {e}"
         return None
 
-    def _discard_backup(self, plugin_id: str, backup_path: Path, action: str) -> None:
-        """Remove the set-aside copy after a successful (re)install."""
+    def _discard_backup(
+        self, plugin_id: str, backup_path: Path, action: str,
+        new_path: Optional[Path] = None,
+    ) -> None:
+        """Remove the set-aside copy after a successful (re)install.
+
+        With ``new_path`` (where the new copy landed), first carries the
+        plugin's own runtime files -- OAuth tokens, client secrets, anything
+        its .gitignore excludes -- from the old copy into the new one: no
+        release contains them, so deleting the old copy would destroy them.
+        See src/plugin_system/plugin_local_files.py. If any could not be
+        copied the old copy is kept, so nothing is lost.
+        """
+        if new_path is not None and new_path.is_dir():
+            copied, failed = carry_over_local_files(backup_path, new_path)
+            if copied:
+                self.logger.info(
+                    "Kept %d local file(s) of %s across the %s: %s",
+                    len(copied), plugin_id, action, ", ".join(copied))
+            if failed:
+                self.logger.error(
+                    "Could not carry %s's local files into the new copy (%s); "
+                    "the previous copy is kept at %s -- copy them back by hand",
+                    plugin_id,
+                    "; ".join(f"{rel}: {err}" for rel, err in failed),
+                    backup_path)
+                return
         if not self._safe_remove_directory(backup_path):
             self.logger.warning(
                 "%s of %s succeeded but the previous copy at %s could not be "
@@ -542,7 +570,8 @@ class _InstallMixin:
                     raise
                 temp_dir = None  # Prevent cleanup since we moved it
                 if backup_path is not None:
-                    self._discard_backup(plugin_id, backup_path, "install")
+                    self._discard_backup(
+                        plugin_id, backup_path, "install", new_path=final_path)
 
             # Install dependencies
             self._install_dependencies(final_path)

src/plugin_system/store_manager.py

@@ -138,6 +138,11 @@ class PluginStoreManager(_RegistryMixin, _InstallMixin, _UpdateMixin):
         # the registry cache expires. Only one thread fetches; others wait and
         # then get the result from the warm cache (double-checked locking).
         self._registry_fetch_lock = threading.Lock()
+        # refresh_registry_in_background: the one refresh thread, and when
+        # an offline one may be retried (see that method).
+        self._registry_refresh_lock = threading.Lock()
+        self._registry_refresh_thread: Optional[threading.Thread] = None
+        self._registry_refresh_retry_after = 0.0
 
         # Per-plugin locks for _reinstall_with_rollback: the web UI runs
         # Flask with threaded=True, so two overlapping requests for the

src/plugin_system/store_registry.py

@@ -7,6 +7,7 @@ methods reach shared state and helpers through ``self``.
 
 import json
 import requests
+import threading
 import time
 from concurrent.futures import ThreadPoolExecutor
 from datetime import datetime
@@ -985,10 +986,14 @@ class _RegistryMixin:
 
     def get_registry_info(self, plugin_id: str) -> Optional[Dict]:
         """
-        Get plugin information from the registry cache only (no GitHub API calls).
+        Get plugin information from the registry (plugins.json).
 
-        Use this for lightweight lookups where only registry fields are needed
-        (e.g., verified status, latest_version).
+        Makes no GitHub API calls, but it does go through `fetch_registry`:
+        when the in-memory copy is missing or older than
+        ``registry_cache_timeout`` it downloads plugins.json, and with no
+        network that waits out the timeout and retries. A caller that must
+        not block on the network (the installed-plugins list) uses
+        `get_cached_registry_info` instead.
 
         Args:
             plugin_id: Plugin identifier
@@ -999,3 +1004,52 @@ class _RegistryMixin:
         registry = self.fetch_registry()
         plugins = registry.get('plugins', []) or []
         return self._match_registry_entry(plugins, plugin_id)
+
+    def get_cached_registry_info(self, plugin_id: str) -> Optional[Dict]:
+        """The registry entry for ``plugin_id`` from the copy already in
+        memory, however old; never touches the network.
+
+        None when no registry has been loaded yet, or the plugin isn't in it.
+        When the copy is missing or past ``registry_cache_timeout`` this
+        starts `refresh_registry_in_background`, so a later call has it.
+        """
+        cache = getattr(self, 'registry_cache', None)
+        cache_time = getattr(self, 'registry_cache_time', None)
+        if (not cache or not cache_time
+                or (time.time() - cache_time) >= self.registry_cache_timeout):
+            self.refresh_registry_in_background()
+        plugins = cache.get('plugins') if isinstance(cache, dict) else None
+        if not isinstance(plugins, list):
+            return None
+        return self._match_registry_entry(
+            [p for p in plugins if isinstance(p, dict)], plugin_id)
+
+    def refresh_registry_in_background(self) -> bool:
+        """Fetch the registry on a daemon thread; True when one was started.
+
+        At most one runs at a time. After a fetch that left no registry in
+        memory (offline), no new one starts for ``_failure_backoff_seconds``,
+        so an offline Pi doesn't retry on every page load.
+        """
+        with self._registry_refresh_lock:
+            running = self._registry_refresh_thread
+            if running is not None and running.is_alive():
+                return False
+            if time.time() < self._registry_refresh_retry_after:
+                return False
+            thread = threading.Thread(
+                target=self._background_registry_refresh,
+                name='registry-refresh', daemon=True)
+            self._registry_refresh_thread = thread
+            thread.start()
+            return True
+
+    def _background_registry_refresh(self) -> None:
+        try:
+            self.fetch_registry()
+        except Exception as e:  # noqa: BLE001 - a background warm-up must not crash
+            self.logger.warning("Background registry refresh failed: %s", e)
+        if not getattr(self, 'registry_cache', None):
+            with self._registry_refresh_lock:
+                self._registry_refresh_retry_after = (
+                    time.time() + self._failure_backoff_seconds)

src/plugin_system/store_update.py

@@ -10,6 +10,9 @@ import subprocess  # nosec B404 - list-form argv only, no shell  # nosemgrep
 from pathlib import Path
 from typing import Dict, Optional, Tuple
 from src.plugin_system.plugin_dirs import BACKUP_MARKER
+from src.plugin_system.plugin_local_files import (
+    KNOWN_STATE_PATTERNS, is_known_state_file,
+)
 from src.plugin_system.repo_urls import same_repo
 
 
@@ -302,7 +305,11 @@ class _UpdateMixin:
                 installed = False
 
             if installed:
-                self._discard_backup(plugin_id, backup_path, "update")
+                # install_plugin may land the new copy under the manifest id
+                # rather than the old directory name.
+                self._discard_backup(
+                    plugin_id, backup_path, "update",
+                    new_path=self._existing_install(plugin_id) or plugin_path)
                 return True
 
             # Bad network, registry error...: the user keeps a working plugin.
@@ -509,8 +516,12 @@ class _UpdateMixin:
                             for line in untracked_result.stdout.strip().split('\n'):
                                 if line.startswith('??'):
                                     # Untracked file
-                                    file_path = line[3:].strip()
-                                    untracked_files.append(file_path)
+                                    file_path = line[3:].strip().strip('"')
+                                    # Tokens and secrets stay out of the
+                                    # stash (see below), so they alone are
+                                    # not a reason to stash.
+                                    if not is_known_state_file(file_path):
+                                        untracked_files.append(file_path)
                         
                         # Check for tracked file changes
                         status_result = subprocess.run(
@@ -537,9 +548,17 @@ class _UpdateMixin:
                     if has_changes:
                         self.logger.info(f"Stashing local changes in {plugin_id} before update")
                         try:
-                            # Use -u to include untracked files in stash
+                            # Use -u to include untracked files in stash --
+                            # except the plugin's tokens and secrets, which a
+                            # repo may have forgotten to gitignore. The stash
+                            # is never popped, so a stashed token.pickle would
+                            # vanish from the plugin and break it.
+                            stash_cmd = (
+                                ['git', '-C', str(plugin_path), 'stash', 'push', '-u',
+                                 '-m', f'LEDMatrix auto-stash before update {plugin_id}', '--', '.']
+                                + [f':(exclude,glob)**/{p}' for p in KNOWN_STATE_PATTERNS])
                             stash_result = subprocess.run(
-                                ['git', '-C', str(plugin_path), 'stash', 'push', '-u', '-m', f'LEDMatrix auto-stash before update {plugin_id}'],
+                                stash_cmd,
                                 capture_output=True,
                                 text=True,
                                 timeout=30,

src/screen_runner.py

@@ -0,0 +1,484 @@
+"""Runs one screen: the ScreenRunner of docs/RUN_LOOP_REDESIGN.md.
+
+``ScreenRunner.run(plan, plugin)`` draws a screen's first frame, runs the
+frame loop its plan's ``frame_policy`` picks (125 Hz or 1 Hz), makes up the
+minimum duration when the loop ended early, and returns one
+:class:`Outcome` saying why the screen ended. Everything that touches the
+plugin, the panel or the controller's state goes through a
+:class:`ScreenHost` (the DisplayController); everything that reads or waits
+on the clock goes through an injected :class:`FrameClock`. The runner itself
+holds no state between screens.
+
+What can end a screen early is decided at the runner's service points: after
+each frame, after the frame loop, and after the make-up dwell. At each one
+the host gathers a snapshot and asks the Arbiter, once, whether a Source in
+``plan.preemptible_by`` now wants the panel (:meth:`ScreenHost.check`). A yes
+is ``ExitReason.PREEMPTED``: the next pass of the loop decides what shows,
+and the rotation does not advance past the screen that was cut short.
+
+The frame pacing is the loop that used to be inline in
+``DisplayController.run()``, unchanged: the 125 Hz loop paces to an 8 ms
+deadline from the start of each frame (sleeping at least 1 ms, so a frame
+that overran still yields the GIL), and the 1 Hz loop sleeps a flat second
+between frames, woken early by a control socket command.
+"""
+
+import logging
+from dataclasses import dataclass
+from enum import Enum
+from typing import Any, NamedTuple, Optional, Protocol, Tuple
+
+from src.display_arbiter import FramePolicy, ScreenPlan, Source
+
+__all__ = [
+    "AFTER_COMPLETED_LOOP",
+    "AFTER_LOOP",
+    "Checkpoint",
+    "DYNAMIC_GRACE",
+    "ExitReason",
+    "FINAL",
+    "FRAME",
+    "FirstFrame",
+    "FrameClock",
+    "HIGH_FPS_INTERVAL",
+    "NoticeRead",
+    "Outcome",
+    "STATIC_INTERVAL",
+    "Screen",
+    "ScreenHost",
+    "ScreenRunner",
+    "after_dwell",
+]
+
+#: Seconds between frames in the high-FPS loop (125 Hz), for scrolling plugins.
+HIGH_FPS_INTERVAL = 0.008
+
+#: Seconds between frames in the static loop (1 Hz).
+STATIC_INTERVAL = 1.0
+
+#: A dynamic-duration screen ends on cycle completion only this long after its
+#: minimum, so timing jitter around the minimum can't end it early.
+DYNAMIC_GRACE = 0.5
+
+
+class ExitReason(Enum):
+    """Why a screen ended. The value is the golden traces' exit column where
+    one exists (test/test_run_loop_golden.py)."""
+
+    #: The screen ran its target duration.
+    DURATION = "duration"
+    #: A dynamic-duration plugin finished its cycle after its minimum.
+    CYCLE_COMPLETE = "cycle-complete"
+    #: The first frame had nothing to show (display() returned False or
+    #: raised inside the executor), or no plugin draws the mode.
+    EMPTY = "empty"
+    #: The first frame's dispatch itself raised.
+    ERROR = "error"
+    #: A later frame returned False (a dynamic-duration screen on the 1 Hz
+    #: loop keeps going instead).
+    DISPLAY_FALSE = "display-false"
+    #: Another Source took the panel, or an on-demand session ran out before
+    #: the screen began. The rotation does not advance.
+    PREEMPTED = "preempted"
+    #: A plugin reload is waiting for the top of the loop. The screen is cut
+    #: short but counts as shown: the rotation advances, and the next pass
+    #: reloads before it draws.
+    RELOAD = "reload"
+
+
+@dataclass(frozen=True)
+class Outcome:
+    """How a screen ended.
+
+    Attributes:
+        exit_reason: Why it ended.
+        elapsed: Seconds from the end of the first frame to the end.
+        preempted_by: For PREEMPTED, the plan that took the panel when the
+            Arbiter named one (None when the session simply ran out).
+        on_demand_active: Filled in by the controller when the screen is
+            over: an on-demand session was running at that moment.
+        still_live: Filled in by the controller: the mode's plugin still had
+            live content at that moment, which holds the rotation on it.
+    """
+
+    exit_reason: ExitReason
+    elapsed: float = 0.0
+    preempted_by: Optional[ScreenPlan] = None
+    on_demand_active: bool = False
+    still_live: bool = False
+
+
+class FrameClock(Protocol):
+    """The clocks the runner reads and the sleep it paces with.
+
+    The shape of the ``time`` module, so production passes it (through an
+    indirection that lets tests patch the module) and the golden traces pass
+    their fake clock.
+    """
+
+    def time(self) -> float:
+        """Wall-clock seconds: what screen durations are measured in."""
+
+    def perf_counter(self) -> float:
+        """A monotonic high-resolution clock: what the 8 ms pacing reads."""
+
+    def sleep(self, seconds: float) -> None:
+        """Block for ``seconds``."""
+
+
+class NoticeRead(Enum):
+    """When a service point reads the WiFi notice file.
+
+    The read is throttled to once a second and deletes an expired file, so
+    *when* it happens is behaviour: each service point reads it exactly
+    when the loop always did.
+    """
+
+    #: Not at all.
+    NEVER = "never"
+    #: Only if nothing cheaper has already ended the screen: no on-demand
+    #: session, the panel on, the mode unchanged and no live takeover.
+    IF_UNDECIDED = "if-undecided"
+    #: Whenever no on-demand session is running.
+    ALWAYS = "always"
+
+
+@dataclass(frozen=True)
+class Checkpoint:
+    """What one kind of service point considers.
+
+    Attributes:
+        name: For logs and tests.
+        notice: When the WiFi notice is read (see NoticeRead).
+        notice_counts: Whether a pending notice ends the screen here. After
+            the make-up dwell it does only while the screen had time left.
+        reload: Whether a pending plugin reload ends the screen here. Only
+            between frames: once the frame loop is over the screen is too.
+    """
+
+    name: str
+    notice: NoticeRead
+    reload: bool
+    notice_counts: bool = True
+
+
+#: Between frames: the frame loops' check, and the socket wake in the 1 Hz wait.
+FRAME = Checkpoint("frame", NoticeRead.IF_UNDECIDED, reload=True)
+#: After a frame loop that ended early (display() returned False, a reload).
+AFTER_LOOP = Checkpoint("after-loop", NoticeRead.IF_UNDECIDED, reload=False)
+#: After a frame loop that ran its course: only a mode change or the schedule.
+AFTER_COMPLETED_LOOP = Checkpoint("after-completed-loop", NoticeRead.NEVER, reload=False)
+#: The last look before the rotation advances.
+FINAL = Checkpoint("final", NoticeRead.NEVER, reload=False)
+
+
+def after_dwell(time_left: bool) -> Checkpoint:
+    """After the make-up dwell: a notice that cut it short ends the screen,
+    so the mode resumes after the notice instead of rotating past it."""
+    return Checkpoint("after-dwell", NoticeRead.ALWAYS, reload=False,
+                      notice_counts=time_left)
+
+
+class FirstFrame(NamedTuple):
+    """What the first frame's dispatch returned (see _dispatch_first_frame)."""
+
+    shown: bool
+    raised: bool
+    accepts_display_mode: bool
+
+
+@dataclass
+class Screen:
+    """One running screen: its completed plan, the plugin drawing it and
+    when it started. Mutable only in that the runner owns it."""
+
+    plan: ScreenPlan
+    plugin: Any
+    accepts_display_mode: bool
+    start: float
+
+    @property
+    def mode(self) -> Optional[str]:
+        return self.plan.mode
+
+
+class ScreenHost(Protocol):
+    """The controller's side of a screen. See DisplayController."""
+
+    def first_frame(self, plan: ScreenPlan, plugin: Any) -> FirstFrame:
+        """Draw the first frame through the plugin executor."""
+
+    def complete_plan(self, plan: ScreenPlan, plugin: Any) -> Optional[ScreenPlan]:
+        """The plan with the plugin's durations, dynamic flag and frame
+        policy, read after the first frame. None when an on-demand session
+        has no time left for it."""
+
+    def draw(self, screen: Screen) -> Any:
+        """One later frame: what display() returned."""
+
+    def after_frame(self, screen: Screen) -> None:
+        """After a frame that did not end the screen (the follower frame)."""
+
+    def tick(self) -> None:
+        """Plugin updates that have come due (throttled)."""
+
+    def service(self, screen: Screen) -> Optional[Tuple[str, ...]]:
+        """Apply pending changes (on-demand requests, schedule, brightness,
+        finished reloads). Returns the live modes when a live-priority scan
+        was due, else None."""
+
+    def wait_frame(self, interval: float, screen: Screen) -> Optional[ScreenPlan]:
+        """The 1 Hz loop's sleep between frames. The plan that takes the
+        panel when a control socket command ended the screen, else None."""
+
+    def check(self, screen: Screen, checkpoint: Checkpoint,
+              live_scan: Optional[Tuple[str, ...]] = None) -> Optional[ScreenPlan]:
+        """The service point: the plan that now takes the panel from this
+        screen, or None while it holds. One Arbiter.decide() call."""
+
+    def dwell(self, seconds: float) -> None:
+        """Sleep up to ``seconds``, servicing changes; returns early on one."""
+
+    def cycle_complete(self, screen: Screen) -> bool:
+        """The plugin's dynamic-duration cycle is complete."""
+
+
+class ScreenRunner:
+    """Runs one screen at a time for a ScreenHost. See the module docstring."""
+
+    def __init__(self, clock: FrameClock, host: ScreenHost,
+                 log: Optional[logging.Logger] = None):
+        self.clock = clock
+        self.host = host
+        # The controller passes its own logger, so these lines keep the
+        # source they always had in the journal.
+        self.log = log or logging.getLogger(__name__)
+
+    # -- the screen ------------------------------------------------------
+
+    def run(self, plan: ScreenPlan, plugin: Any) -> Outcome:
+        """Run ``plan``'s screen, drawn by ``plugin`` (None: nothing draws it)."""
+        if plugin is None:
+            return Outcome(ExitReason.EMPTY)
+        first = self.host.first_frame(plan, plugin)
+        if not first.shown:
+            return Outcome(ExitReason.ERROR if first.raised else ExitReason.EMPTY)
+        completed = self.host.complete_plan(plan, plugin)
+        if completed is None:
+            return Outcome(ExitReason.PREEMPTED)
+        screen = Screen(completed, plugin, first.accepts_display_mode,
+                        start=self.clock.time())
+
+        if completed.frame_policy is FramePolicy.HIGH_FPS:
+            reason, by = self._high_fps_loop(screen)
+        else:
+            reason, by = self._static_loop(screen)
+        if reason is ExitReason.PREEMPTED:
+            # The service point that ended the loop has decided; looking
+            # again now, at the same instant, gives the same answer.
+            return self._outcome(screen, reason, by)
+
+        loop_completed = reason in (ExitReason.DURATION, ExitReason.CYCLE_COMPLETE)
+        # LOAD-BEARING: a change the frame loop did not end on (a dwell
+        # inside it, a later frame returning False) must not fall into the
+        # make-up dwell below. It can run for the rest of the screen's
+        # duration, and a freshly requested on-demand mode would sit
+        # invisible for that long -- or be clobbered by a queued stop.
+        by = self.host.check(screen, AFTER_COMPLETED_LOOP if loop_completed else AFTER_LOOP)
+        if by is not None:
+            return self._outcome(screen, ExitReason.PREEMPTED, by)
+
+        # Honour the minimum duration when a static, non-dynamic screen's
+        # loop ended early. A screen cut short for a plugin reload is over:
+        # the dwell returns at once and the rotation advances.
+        if (not completed.dynamic and not loop_completed
+                and completed.frame_policy is not FramePolicy.HIGH_FPS):
+            elapsed = self.clock.time() - screen.start
+            remaining = max(0.0, self._max(screen) - elapsed)
+            if remaining > 0:
+                self.host.dwell(remaining)
+                time_left = self.clock.time() - screen.start < self._max(screen)
+                by = self.host.check(screen, after_dwell(time_left))
+                if by is not None:
+                    return self._outcome(screen, ExitReason.PREEMPTED, by)
+
+        if completed.dynamic:
+            self._log_dynamic_end(screen)
+
+        # The dwells above return early when a pending change (on-demand
+        # started or stopped, the panel scheduled off) has already decided
+        # what comes next; rotating now would skip it.
+        by = self.host.check(screen, FINAL)
+        if by is not None:
+            return self._outcome(screen, ExitReason.PREEMPTED, by)
+        return self._outcome(screen, reason, None)
+
+    def _outcome(self, screen: Screen, reason: ExitReason,
+                 by: Optional[ScreenPlan]) -> Outcome:
+        return Outcome(reason, self.clock.time() - screen.start, preempted_by=by)
+
+    @staticmethod
+    def _max(screen: Screen) -> float:
+        return float(screen.plan.max_duration or 0.0)
+
+    @staticmethod
+    def _min(screen: Screen) -> float:
+        return float(screen.plan.min_duration or 0.0)
+
+    @staticmethod
+    def _ended_by(by: ScreenPlan) -> ExitReason:
+        return ExitReason.RELOAD if by.source is Source.RELOAD else ExitReason.PREEMPTED
+
+    # -- the frame loops ---------------------------------------------------
+
+    def _high_fps_loop(self, screen: Screen) -> Tuple[ExitReason, Optional[ScreenPlan]]:
+        """Ultra-smooth frames for scrolling plugins (8 ms = 125 FPS)."""
+        clock, host, log = self.clock, self.host, self.log
+        interval = HIGH_FPS_INTERVAL
+        log.debug("Entering high-FPS loop for %s with display_interval=%.3fs (%.1f FPS)",
+                  screen.mode, interval, 1.0 / interval)
+        target = self._max(screen)
+        while True:
+            frame_start = clock.perf_counter()
+            try:
+                result = host.draw(screen)
+                if isinstance(result, bool) and not result:
+                    log.debug("Display returned False, breaking early")
+                    return ExitReason.DISPLAY_FALSE, None
+            except Exception:  # pylint: disable=broad-except
+                log.exception("Error during display update")
+
+            # Multi-display sync: send follower frame after each render
+            host.after_frame(screen)
+            host.tick()
+            # Throttled: one clock compare between passes. A live-priority
+            # scan, when one is due, happens here, before the sleep, as it
+            # always has; the Arbiter weighs it after the sleep.
+            live_scan = host.service(screen)
+
+            # Pace to the frame deadline rather than sleeping a flat
+            # interval on top of the work. display() has already blocked on
+            # the panel's vsync by this point, so an unconditional sleep is
+            # added to a wait that already happened. Measured on a 2x128x64
+            # chain at limit_refresh_rate_hz=100: ~4ms of render plus a flat
+            # 8ms put each iteration at ~12ms against a 10ms refresh grid, so
+            # every swap missed a refresh and the loop settled at 50fps where
+            # display_interval asks for 125 -- and with zero headroom, ~14% of
+            # frames slipped a further refresh, which is what reads as scroll
+            # stutter.
+            remaining = interval - (clock.perf_counter() - frame_start)
+            # Yield even when the frame overran its budget, so plugin update
+            # threads and the web UI are not starved of the GIL.
+            clock.sleep(remaining if remaining > 0 else 0.001)
+
+            by = host.check(screen, FRAME, live_scan)
+            if by is not None:
+                log.debug("Mode changed during high-FPS loop, breaking early")
+                return self._ended_by(by), by
+
+            elapsed = clock.time() - screen.start
+            if elapsed >= target:
+                log.debug("Reached high-FPS target duration %.2fs for mode %s",
+                          target, screen.mode)
+                return ExitReason.DURATION, None
+            if self._should_exit_dynamic(screen, elapsed):
+                log.debug("Dynamic duration cycle complete for %s after %.2fs",
+                          screen.mode, elapsed)
+                return ExitReason.CYCLE_COMPLETE, None
+
+    def _static_loop(self, screen: Screen) -> Tuple[ExitReason, Optional[ScreenPlan]]:
+        """One frame a second for everything else."""
+        clock, host, log = self.clock, self.host, self.log
+        interval = STATIC_INTERVAL
+        log.debug("Entering normal FPS loop for %s with display_interval=%.3fs",
+                  screen.mode, interval)
+        target = self._max(screen)
+        dynamic = screen.plan.dynamic
+        while True:
+            # Wakes for a control socket command and applies it at once,
+            # instead of up to a second later.
+            by = host.wait_frame(interval, screen)
+            if by is not None:
+                log.info("Mode changed during display loop from %s to %s (%s), "
+                         "breaking early", screen.mode, by.mode, by.source.value)
+                return self._ended_by(by), by
+            host.tick()
+
+            elapsed = clock.time() - screen.start
+            if elapsed >= target:
+                log.debug("Reached standard target duration %.2fs for mode %s",
+                          target, screen.mode)
+                return ExitReason.DURATION, None
+
+            try:
+                result = host.draw(screen)
+                if isinstance(result, bool) and not result:
+                    # A dynamic-duration screen doesn't end on False: it
+                    # keeps looping until its cycle completes or its maximum.
+                    if not dynamic:
+                        log.info("Display returned False for %s (no dynamic duration), "
+                                 "breaking early", screen.mode)
+                        return ExitReason.DISPLAY_FALSE, None
+                    log.debug("Display returned False for %s (dynamic duration enabled), "
+                              "continuing loop", screen.mode)
+            except Exception:  # pylint: disable=broad-except
+                log.exception("Error during display update")
+
+            # Multi-display sync: send follower frame after each render
+            host.after_frame(screen)
+
+            live_scan = host.service(screen)
+            by = host.check(screen, FRAME, live_scan)
+            if by is not None:
+                log.info("Mode changed during display loop from %s to %s (%s), "
+                         "breaking early", screen.mode, by.mode, by.source.value)
+                return self._ended_by(by), by
+
+            if self._should_exit_dynamic(screen, elapsed):
+                log.info("Dynamic duration cycle complete for %s after %.2fs",
+                         screen.mode, elapsed)
+                return ExitReason.CYCLE_COMPLETE, None
+
+    # -- dynamic duration --------------------------------------------------
+
+    def _should_exit_dynamic(self, screen: Screen, elapsed: float) -> bool:
+        if not screen.plan.dynamic:
+            return False
+        minimum = self._min(screen)
+        # A small grace period after min_duration prevents premature exits
+        # due to timing issues.
+        if elapsed < minimum + DYNAMIC_GRACE:
+            self.log.debug(
+                "_should_exit_dynamic: elapsed %.2fs < min_duration %.2fs + grace %.2fs, "
+                "returning False", elapsed, minimum, DYNAMIC_GRACE)
+            return False
+        cycle_complete = self.host.cycle_complete(screen)
+        self.log.debug(
+            "_should_exit_dynamic: elapsed %.2fs >= min %.2fs, cycle_complete=%s, returning %s",
+            elapsed, minimum + DYNAMIC_GRACE, cycle_complete, cycle_complete)
+        if cycle_complete:
+            self.log.debug("Cycle complete detected for %s after %.2fs (min: %.2fs, grace: %.2fs)",
+                           screen.mode, elapsed, minimum, DYNAMIC_GRACE)
+        return cycle_complete
+
+    def _log_dynamic_end(self, screen: Screen) -> None:
+        """How a dynamic-duration screen ended, for the log. Asks the plugin
+        once more whether its cycle is complete, as the loop always did."""
+        elapsed_total = self.clock.time() - screen.start
+        cycle_done = self.host.cycle_complete(screen)
+        minimum, maximum = self._min(screen), self._max(screen)
+        if cycle_done:
+            self.log.info(
+                "Dynamic duration cycle completed for %s after %.2fs "
+                "(target: %.2fs, min: %.2fs, max: %.2fs)",
+                screen.mode, elapsed_total, maximum, minimum, maximum)
+        elif elapsed_total >= maximum:
+            self.log.info(
+                "Dynamic duration cap reached before cycle completion for %s "
+                "(%.2fs/%ds, min: %.2fs)",
+                screen.mode, elapsed_total, int(maximum), minimum)
+        else:
+            self.log.debug(
+                "Dynamic duration cycle in progress for %s: %.2fs elapsed "
+                "(target: %.2fs, min: %.2fs, max: %.2fs)",
+                screen.mode, elapsed_total, maximum, minimum, maximum)

src/vegas_mode/coordinator.py

@@ -18,11 +18,10 @@ import math
 import sys
 import time
 import threading
-from typing import Optional, Dict, Any, FrozenSet, List, Callable, TYPE_CHECKING
+from typing import Optional, Dict, Any, List, Callable, TYPE_CHECKING
 
 from src import display_watchdog
 from src.common import render_gate
-from src.plugin_system.base_plugin import finite_seconds
 from src.vegas_mode.config import VegasModeConfig
 from src.vegas_mode.elements import LiveEpochs
 from src.vegas_mode.plugin_adapter import PluginAdapter
@@ -54,14 +53,6 @@ _FPS_HEARTBEAT_INTERVAL = 300.0
 #: every plugin. Game state doesn't change within a quarter second.
 _LIVE_PRIORITY_CHECK_INTERVAL = 0.25
 
-#: Seconds a static pause shows a plugin whose display duration can't be
-#: used, as long as the rotation shows it: 30 when get_display_duration()
-#: raises or answers something that is not a number
-#: (DisplayController._get_display_duration), 15 when it answers a number at
-#: or below zero (DisplayController._resolve_durations).
-_UNREADABLE_DURATION = 30.0
-_NOT_POSITIVE_DURATION = 15.0
-
 
 def _percentile(ordered: List[float], fraction: float) -> float:
     """Nearest-rank percentile of an already-sorted list.
@@ -101,9 +92,6 @@ class VegasModeCoordinator:
     _live_reason: Optional[str] = None
     # Set only while Vegas has changed the GIL switch interval; read with getattr.
     _saved_switch_interval: Optional[float]
-    #: Plugins already warned about a display duration the pause can't use,
-    #: so a bad setting logs once, not at every turn. Replaced, not mutated.
-    _duration_warned: FrozenSet[str] = frozenset()
 
     def __init__(
         self,
@@ -1022,7 +1010,7 @@ class VegasModeCoordinator:
             # Wait for the plugin's display duration. Monotonic, like the
             # iteration clock: an NTP step on an RTC-less Pi would otherwise
             # end the pause at once or stretch it by the correction.
-            duration = self._static_pause_duration(plugin)
+            duration = plugin.get_display_duration()
             start = time.monotonic()
 
             while time.monotonic() - start < duration:
@@ -1058,42 +1046,6 @@ class VegasModeCoordinator:
 
         return True
 
-    def _static_pause_duration(self, plugin: 'BasePlugin') -> float:
-        """Seconds a static pause shows ``plugin``: its display duration,
-        read the way the rotation reads it.
-
-        Several plugins return their display_duration setting straight from
-        config.json, so one saved as "20" or null came back as a string or
-        None; comparing it with the clock raised, and the pause's broad
-        except ended the pause at every one of the plugin's turns. inf
-        paused until something interrupted it, and NaN, False, 0 or a
-        negative number ended the pause at once. A numeric string counts
-        (finite_seconds); anything else, or a raise, gets
-        _UNREADABLE_DURATION, and a number at or below zero
-        _NOT_POSITIVE_DURATION, logged once per plugin.
-        """
-        try:
-            value = plugin.get_display_duration()
-        except Exception as err:  # pylint: disable=broad-except
-            problem = f"get_display_duration() raised {type(err).__name__}: {err}"
-            fallback = _UNREADABLE_DURATION
-        else:
-            seconds = finite_seconds(value)
-            if seconds is not None and seconds > 0:
-                return seconds
-            if seconds is None:
-                problem = f"display duration {value!r} is not a number"
-                fallback = _UNREADABLE_DURATION
-            else:
-                problem = f"display duration {value!r} is not above zero"
-                fallback = _NOT_POSITIVE_DURATION
-        plugin_id = plugin.plugin_id
-        if plugin_id not in self._duration_warned:
-            self._duration_warned = self._duration_warned | {plugin_id}
-            logger.warning("[%s] %s; its static pause lasts %.0fs (logged once)",
-                           plugin_id, problem, fallback)
-        return fallback
-
     def _end_static_pause(self) -> None:
         """End static pause and restore scroll state."""
         should_resume_scrolling = False

test/_run_loop_harness.py

@@ -143,12 +143,24 @@ class FakeCache:
     def __init__(self):
         self.data: Dict[str, Any] = {}
         self.cache_dir = "/nonexistent/run-loop-harness"
+        self._writes = 0
+        self._written: Dict[str, int] = {}
 
     def get(self, key, max_age=None, memory_ttl=None):
         return self.data.get(key)
 
     def set(self, key, data, ttl=None):
         self.data[key] = data
+        # Every write is a new file, as DiskCache's rename makes it.
+        self._writes += 1
+        self._written[key] = self._writes
+
+    def file_signature(self, key):
+        """CacheManager.file_signature: None without a file, else a value
+        that changes with every write."""
+        if key not in self.data:
+            return None
+        return (self._written.get(key, 0), 0, 0)
 
     def delete(self, key):
         self.data.pop(key, None)
@@ -724,11 +736,14 @@ class RunLoopHarness:
         self.clock.at(t, post)
 
     def restore_on_demand(self, plugin_id: str, mode: Optional[str] = None,
-                          duration: Optional[float] = None, pinned: bool = False):
+                          duration: Optional[float] = None, pinned: bool = False,
+                          named_mode: Optional[str] = None):
         """Start with an on-demand session resumed from the cache, as after
         a restart: the state _select_startup_plugins restores, then
-        _populate_on_demand_modes_from_plugin, as __init__ calls it."""
+        _populate_on_demand_modes_from_plugin, as __init__ calls it. A
+        session that cannot resume is logged as ``on-demand-error``."""
         dc = self.controller
+        dc._on_demand_named_mode = named_mode
         dc.on_demand_active = True
         dc.on_demand_plugin_id = plugin_id
         dc.on_demand_mode = mode
@@ -739,6 +754,8 @@ class RunLoopHarness:
         dc.on_demand_status = 'active'
         dc.on_demand_schedule_override = True
         dc._populate_on_demand_modes_from_plugin()
+        if dc.on_demand_status == 'error':
+            self.log("on-demand-error", dc.on_demand_last_error)
 
     def wifi_message(self, t: float, message: str, duration: float = 5):
         def write():

test/fixtures/run_loop_golden/on_demand_named_live.json

@@ -0,0 +1,29 @@
+{
+  "screens": [
+    [0.0, "clock", 5.0, "on-demand-start", 6, false],
+    [5.0, "sports_live", 15.0, "duration", 15, true],
+    [20.0, "sports_recent", 15.0, "duration", 15, true],
+    [35.0, "sports_upcoming", 5.0, "on-demand-requested-stop", 6, true],
+    [40.0, "clock", 20.0, "duration", 20, true],
+    [60.0, "sports_live", 15.0, "display-false", 11, true],
+    [75.0, "sports_recent", 15.0, "duration", 15, true],
+    [90.0, "sports_upcoming", 10.0, "on-demand-start", 11, true],
+    [100.0, "sports_live", 0.0, "empty", 1, true],
+    [100.0, "sports_recent", 15.0, "duration", 15, true],
+    [115.0, "sports_upcoming", 15.0, "duration", 15, true],
+    [130.0, "sports_live", 0.0, "empty", 1, true],
+    [130.0, "sports_recent", 10.0, "on-demand-requested-stop", 11, true],
+    [140.0, "sports_upcoming", 15.0, "duration", 15, true],
+    [155.0, "clock", 5.0, "horizon", 5, true]
+  ],
+  "events": [
+    [5.0, "request", "start:n1"],
+    [5.0, "on-demand-start", "sports"],
+    [40.0, "request", "stop:n2"],
+    [40.0, "on-demand-requested-stop"],
+    [100.0, "request", "start:n3"],
+    [100.0, "on-demand-start", "sports"],
+    [140.0, "request", "stop:n4"],
+    [140.0, "on-demand-requested-stop"]
+  ]
+}

test/fixtures/run_loop_golden/on_demand_restore_failed.json

@@ -0,0 +1,10 @@
+{
+  "screens": [
+    [0.0, "clock", 20.0, "duration", 20, false],
+    [20.0, "weather", 20.0, "duration", 20, true],
+    [40.0, "clock", 20.0, "horizon", 20, true]
+  ],
+  "events": [
+    [0.0, "on-demand-error", "restore-failed"]
+  ]
+}

test/js/README.md

@@ -59,8 +59,8 @@ server has none.
 | `unit/test_page_registry.js` | no | The page lifecycle in `js/core/registry.js` (a minimal DOM shim): one `init` per `data-page` root, `destroy` and an aborted `ctx.signal` when htmx swaps it away, a vetoed swap keeps it, lazy page modules, a root removed without htmx swept on the next swap |
 | `unit/test_core_modules.js` | no | `js/core/api.js` (JSON envelope, HTTP/`status: error`/network errors, abort passthrough, the #683 login redirect, same-server paths only) and `js/core/facade.js` (`window.LEDMatrix`, deprecated aliases) |
 | `unit/test_overview_reconciliation_poll.js` | no | The Overview's reconciliation-banner poll from `partials/overview.html`, run in a vm: it gives up after a bounded number of requests when the status never says done, runs only while the Overview is on screen (`LEDVisibility`, its own key), and stops once the banner is shown |
-| `unit/test_display_partial_ids.js` | no | `partials/display.html`: every literal `getElementById()` in its inline scripts names an id the partial renders, and moving the brightness slider (the shipped script, in a vm with a fake DOM) updates its label without throwing |
-| `unit/test_general_web_login_token.js` | no | `window.webLogin.createToken` from `partials/general.html`, run in a vm: a created API token clears the form's `data-dirty` mark (so a reload does not ask "Leave site?"), a refused one keeps it |
+| `unit/test_display_partial_ids.js` | no | `js/pages/display.js` started on a fake root that answers only for the ids `partials/display.html` renders: every id it looks up (with every listener and timer it set fired) exists, and moving the brightness slider updates its label without throwing |
+| `unit/test_general_web_login_token.js` | no | `createToken` from `js/pages/general.js`, imported with a fake DOM and fetch: a created API token clears the form's `data-dirty` mark (so a reload does not ask "Leave site?"), a refused one keeps it |
 | `unit/test_plugin_action_delegation.js` | no | The document-level card-action delegation and `handlePluginAction` from `plugins_manager.js`, run with the handler inside an IIFE as in the real file: each action is handled once, a Starlark app uninstall goes to `DELETE /starlark/apps/<id>`, and an uninstall is confirmed once |
 | `dom/test_installed_dom.js` | yes | The toolbar in a real DOM: pill/search/sort interaction, the HTMX partial re-swap, and a `getComputedStyle` check that `.filter-pill[data-active]` really matches the emitted markup |
 | `dom/test_store_dom.js` | yes | Store pagination, per-page, category, tri-state Installed button, and persistence across a re-boot, against the live registry |
@@ -69,6 +69,10 @@ server has none.
 | `dom/test_durations_page.js` | yes | The Rotation tab (`js/pages/durations.js`) with the real `plugin-order-list.js` widget: one plugin-list request per swap, one move per click after repeated swaps, a swap cancels the request in flight, a late widget is waited for |
 | `dom/test_operation_history_page.js` | yes | The Operation History tab (`js/pages/operation-history.js`): one request per swap and per Refresh, the plugin filter filled once, paging, filters, search, Clear, error/login states, hostile values stay text |
 | `dom/test_raw_json_page.js` | yes | The Config Editor tab (`js/pages/raw-json.js`): one POST per Save after repeated swaps, Format/Validate, invalid JSON never sent, a save survives a swap, the old global entry points |
+| `dom/test_schedule_page.js` | yes | The Schedule tab (`js/pages/schedule.js`) with the real `schedule-picker` widget: both pickers drawn once per swap from the saved config, one notification per save answer after repeated swaps, the brightness label, a late widget waited for, the old global entry points |
+| `dom/test_visibility_service.js` | yes (no server) | `js/core/visibility.js` with the real `LEDVisibility` from `app-shell.js` and the real registry: start/stop with the active tab and the browser tab's visibility, no interval while hidden or after a swap-out, registrations independent, the no-`LEDVisibility` fallback |
+| `dom/test_display_page.js` | yes | The Display tab (`js/pages/display.js`) with the real `plugin-order-list` widget and `LEDVisibility`: one page, one sync interval and one action per control after repeated swaps, the sync poll only while on screen and never after a swap-out, sync states as text, the debounced scroll-speed hint, `updateSyncUI`'s entry point |
+| `dom/test_general_page.js` | yes | The General tab (`js/pages/general.js`) with the real `timezone-selector` widget: the picker drawn once per swap, one request per Security action after repeated swaps, hostile token names stay text, refused/network/login answers, a write survives a swap, `webLogin`'s entry points |
 | `dom/test_backup_restore_page.js` | yes | The Backup & Restore tab (`js/pages/backup-restore.js`): one request per action after repeated swaps, the upload and restore options, reads cancelled and writes not on a swap, hostile names stay text, the old global entry points |
 | `dom/test_tools_sections.js` | yes | The Tools tab's MQTT bridge and Pixlet editor sections: form prefill, the write-only password (blank means unchanged), the running-session banner and countdown, and that the editor link points at the host you loaded the page from |
 

test/js/dom/test_display_page.js

@@ -0,0 +1,325 @@
+// The Display tab as a page module (static/v3/js/pages/display.js), in a
+// real DOM (jsdom) with the real server-rendered partial, the real
+// plugin-order-list widget, the real window.LEDVisibility (app-shell.js)
+// behind ctx.visibility, and the real API's answer shapes. Built like
+// test_cache_page.js:
+//
+//   * the partial ships no <script> and no inline handlers; its root is
+//     data-page="display"
+//   * after five swaps: one mounted page, the Vegas order drawn once, each
+//     control acting once (brightness, resolution, Vegas and double-sided
+//     toggles, the Advanced section toggle, one debounced scroll-speed hint
+//     request)
+//   * the sync status is polled only while the Display tab is on screen and
+//     the browser tab visible: no interval runs while hidden, and none after
+//     the partial is swapped out
+//   * sync states drawn as text; a failed poll says "unavailable", a login
+//     redirect draws nothing
+//   * a widget that loads late is waited for, and a page swapped away while
+//     waiting starts nothing
+//   * window.updateSyncUI's entry point still works
+const http = require('http');
+const fs = require('fs');
+const path = require('path');
+const { pathToFileURL } = require('url');
+const { JSDOM, VirtualConsole } = require('jsdom');
+
+const BASE = process.env.BASE || 'http://localhost:5000';
+const JS = path.resolve(__dirname, '../../../web_interface/static/v3/js');
+const get = p => new Promise((res, rej) =>
+  http.get(BASE + p, r => { let d = ''; r.on('data', c => d += c); r.on('end', () => res(d)); }).on('error', rej));
+const load = f => import(pathToFileURL(path.join(JS, f)).href);
+const tick = ms => new Promise(r => setTimeout(r, ms || 0));
+
+let pass = 0, fail = 0;
+const ok = (l, c, x) => c ? (pass++, console.log('  ok   ' + l))
+  : (fail++, console.log('  FAIL ' + l + (x !== undefined ? '  -> ' + JSON.stringify(x).slice(0, 300) : '')));
+
+(async () => {
+  const partial = await get('/partials/display');
+  const realSync = JSON.parse(await get('/api/v3/sync/status'));
+  const smooth = JSON.parse(await get('/api/v3/config/scroll-speed-advice?speed=50&min=1&max=200'));
+  const rough = JSON.parse(await get('/api/v3/config/scroll-speed-advice?speed=37&min=1&max=200'));
+  const { createRegistry } = await load('core/registry.js');
+  const { createApi } = await load('core/api.js');
+  const { createVisibility } = await load('core/visibility.js');
+  const displayPage = await load('pages/display.js');
+
+  console.log('\n── Display tab: page module (real DOM) ──');
+  ok('the partial ships no inline script', !/<script/i.test(partial));
+  ok('the partial has no inline handlers', !/\son(click|change|input)=/i.test(partial));
+  ok('the partial root is data-page="display"', /data-page="display"/.test(partial));
+  ok('the Advanced toggle names its action',
+     /data-action="toggle-section"\s+data-section="display-section-advanced-hardware"/.test(partial));
+  ok('the real sync status answers in the shape the page reads',
+     realSync.status === 'success' && realSync.data && typeof realSync.data.state === 'string', realSync);
+  ok('the real scroll-speed advice answers in the shape the page reads',
+     smooth.status === 'success' && smooth.data.applied && Array.isArray(rough.data.alternatives)
+       && rough.data.alternatives.length > 0, rough);
+
+  const errs = [];
+  const logged = [];
+  const vc = new VirtualConsole();
+  vc.on('jsdomError', e => errs.push(String(e.message || e).split('\n')[0]));
+  vc.on('error', (...a) => logged.push(a.join(' ')));
+  const dom = new JSDOM(`<!doctype html><html><body><div id="display-content">${partial}</div></body></html>`,
+    { url: BASE + '/', virtualConsole: vc, runScripts: 'outside-only' });
+  const { window } = dom;
+  const doc = window.document;
+  const panel = doc.getElementById('display-content');
+
+  // The browser tab's visibility and the app's active tab, under test control.
+  let hidden = false;
+  Object.defineProperty(doc, 'hidden', { get: () => hidden, configurable: true });
+  const setHidden = v => { hidden = v; doc.dispatchEvent(new window.Event('visibilitychange')); };
+  const setTab = tab => doc.dispatchEvent(new window.CustomEvent('ledmatrix:tab-changed', { detail: { tab } }));
+  // Intervals, counted. Timeouts (the hint's debounce, the widget retry) are real.
+  const intervals = new Map();
+  let nextInterval = 1;
+  window.setInterval = (fn, ms) => { const id = nextInterval++; intervals.set(id, { fn, ms }); return id; };
+  window.clearInterval = id => { intervals.delete(id); };
+  const fireIntervals = () => [...intervals.values()].forEach(i => i.fn());
+
+  const HOSTILE = '<img src=x onerror="window.pwned=1">';
+  const plugins = [
+    { id: 'clock', name: 'Clock', enabled: true },
+    { id: 'weather', name: HOSTILE, enabled: true },
+  ];
+  let syncAnswer = { status: 'success', data: { role: 'leader', state: 'no_peer' } };
+  let syncMode = 'ok';
+  let advice = smooth;
+  const requests = [];
+  function fakeFetch(url, init = {}) {
+    requests.push(url);
+    const respond = (status, body, headers) => Promise.resolve({
+      status, ok: status >= 200 && status < 300,
+      headers: { get: h => (headers || {})[h] || null },
+      json: () => Promise.resolve(body),
+      text: () => Promise.resolve(JSON.stringify(body)),
+    });
+    if (url === '/api/v3/plugins/installed') return respond(200, { status: 'success', data: { plugins } });
+    if (url.startsWith('/api/v3/config/scroll-speed-advice?')) return respond(200, advice);
+    if (url === '/api/v3/sync/status') {
+      if (syncMode === 'network') return Promise.reject(new TypeError('Failed to fetch'));
+      if (syncMode === 'login') return respond(401, { status: 'error' }, { 'X-LEDMatrix-Login': '/login' });
+      return respond(200, syncAnswer);
+    }
+    return respond(404, { status: 'error', message: 'unexpected ' + url });
+  }
+  window.fetch = fakeFetch;
+
+  // The shell: LEDVisibility (no Alpine here, so the active tab is the last
+  // ledmatrix:tab-changed; the SSE streams open stand-in EventSources), and
+  // the shared toggleSection the Advanced button calls.
+  window.getApp = () => null;
+  window.EventSource = class { addEventListener() {} removeEventListener() {} close() {} };
+  window.eval(fs.readFileSync(path.join(JS, 'app-shell.js'), 'utf8'));
+  const toggled = [];
+  window.toggleSection = id => toggled.push(id);
+  window.eval(fs.readFileSync(path.join(JS, 'widgets/plugin-order-list.js'), 'utf8'));
+  const widget = window.PluginOrderList;
+  ok('the widget script defines PluginOrderList', !!(widget && widget.init));
+
+  const visibility = createVisibility({ window });
+  const registry = createRegistry({
+    document: doc,
+    context: { api: createApi({ fetch: fakeFetch }), notify: () => {} },
+    mountContext: ctx => ({ visibility: visibility.forPage(ctx) }),
+  });
+  registry.register('display', displayPage);
+
+  const $ = id => doc.getElementById(id);
+  const root = () => doc.querySelector('[data-page="display"]');
+  const count = prefix => requests.filter(u => u.startsWith(prefix)).length;
+  const syncPolls = () => count('/api/v3/sync/status');
+  async function swap(html) {
+    panel.dispatchEvent(new window.CustomEvent('htmx:beforeSwap', { bubbles: true, detail: { target: panel, shouldSwap: true } }));
+    panel.innerHTML = html === undefined ? partial : html;
+    panel.dispatchEvent(new window.CustomEvent('htmx:afterSwap', { bubbles: true, detail: { target: panel } }));
+    await tick(20);
+  }
+  function fire(el, type) { el.dispatchEvent(new window.Event(type, { bubbles: true })); }
+  function setRole(role) { $('sync_role').value = role; fire($('sync_role'), 'change'); }
+
+  setTab('display');
+  await registry.start();
+  await tick(200);
+
+  // ── first load ──────────────────────────────────────────────────────────
+  ok('one plugin-list request on start', count('/api/v3/plugins/installed') === 1, requests);
+  ok('one scroll-speed hint request on start (after the debounce)', count('/api/v3/config/scroll-speed-advice') === 1, requests);
+  ok('the saved role is standalone: no sync request, no interval work',
+     $('sync_role').value === 'standalone' && syncPolls() === 0, [$('sync_role').value, syncPolls()]);
+  ok('the sync poll interval runs while the tab is on screen', intervals.size === 1
+     && [...intervals.values()][0].ms === 5000, intervals.size);
+  ok('the status bar is hidden for standalone', $('sync_status_bar').classList.contains('hidden'));
+
+  // ── five swaps ──────────────────────────────────────────────────────────
+  for (let i = 0; i < 5; i++) await swap();
+  await tick(200);
+  ok('one mounted page after five swaps', registry.list().length === 1, registry.list().length);
+  ok('one sync interval, not six', intervals.size === 1, intervals.size);
+  ok('one plugin-list request per swap', count('/api/v3/plugins/installed') === 6, count('/api/v3/plugins/installed'));
+  ok('the Vegas order drawn once, not stacked', doc.querySelectorAll('#vegas_plugin_order .plugin-order-item').length === 2,
+     doc.querySelectorAll('#vegas_plugin_order .plugin-order-item').length);
+  ok('a hostile plugin name is shown as text', $('vegas_plugin_order').textContent.includes(HOSTILE)
+     && !doc.querySelector('#vegas_plugin_order img') && !window.pwned);
+
+  // ── the controls ────────────────────────────────────────────────────────
+  $('brightness').value = '42';
+  fire($('brightness'), 'input');
+  ok('the brightness value follows the slider', $('brightness-value').textContent === '42', $('brightness-value').textContent);
+
+  $('rows').value = '32'; $('cols').value = '64'; $('chain_length').value = '3'; $('parallel').value = '2';
+  fire($('parallel'), 'input');
+  ok('the resolution readout is cols x chain by rows x parallel',
+     $('display-resolution-value').textContent === '192 × 64 pixels', $('display-resolution-value').textContent);
+  $('orientation').value = '90';
+  fire($('orientation'), 'change');
+  ok('...swapped for a 90-degree orientation', $('display-resolution-value').textContent === '64 × 192 pixels',
+     $('display-resolution-value').textContent);
+  $('rows').value = '';
+  fire($('rows'), 'input');
+  ok('...and a dash while a field is empty', $('display-resolution-value').textContent === '—');
+
+  for (const [box, settings, shown] of [['vegas_scroll_enabled', 'vegas_scroll_settings', 'block'],
+                                         ['double_sided_enabled', 'double_sided_settings', 'grid']]) {
+    $(box).checked = true; fire($(box), 'change');
+    const on = $(settings).style.display;
+    $(box).checked = false; fire($(box), 'change');
+    ok(`${box} shows and hides its settings`, on === shown && $(settings).style.display === 'none',
+       [on, $(settings).style.display]);
+  }
+
+  root().querySelector('[data-action="toggle-section"]').click();
+  ok('the Advanced button toggles its section once', toggled.join() === 'display-section-advanced-hardware', toggled);
+
+  // ── the scroll-speed hint ───────────────────────────────────────────────
+  const hints = count('/api/v3/config/scroll-speed-advice');
+  advice = rough;
+  for (const v of ['36', '37', '38']) { $('vegas_scroll_speed').value = v; fire($('vegas_scroll_speed'), 'input'); }
+  ok('the speed value follows the slider', $('vegas_scroll_speed_value').textContent === '38');
+  await tick(250);
+  ok('three quick moves make one hint request', count('/api/v3/config/scroll-speed-advice') === hints + 1,
+     count('/api/v3/config/scroll-speed-advice') - hints);
+  ok('...for the last speed', requests.filter(u => u.includes('advice')).pop().includes('speed=38'));
+  const buttons = $('vegas_scroll_speed_hint').querySelectorAll('button');
+  ok('a rough speed offers the smooth ones', buttons.length === rough.data.alternatives.length
+     && /will run as/.test($('vegas_scroll_speed_hint').textContent), $('vegas_scroll_speed_hint').textContent);
+  buttons[0].click();
+  ok('picking one sets the slider', $('vegas_scroll_speed').value === String(Math.round(rough.data.alternatives[0].pixels_per_second))
+     && $('vegas_scroll_speed_value').textContent === $('vegas_scroll_speed').value, $('vegas_scroll_speed').value);
+  advice = smooth;
+  await tick(250);
+  ok('...and asks again', count('/api/v3/config/scroll-speed-advice') === hints + 2);
+  ok('a smooth speed says so', /^Smooth on this panel/.test($('vegas_scroll_speed_hint').textContent),
+     $('vegas_scroll_speed_hint').textContent);
+
+  // ── sync: the role ──────────────────────────────────────────────────────
+  setRole('leader');
+  await tick(20);
+  ok('choosing Leader shows the status bar', !$('sync_status_bar').classList.contains('hidden'));
+  ok('...hides Position', $('setting-display-sync_follower_position').style.display === 'none');
+  ok('...and asks for the status once', syncPolls() === 1, syncPolls());
+  ok('...drawn as text', $('sync_status_content').textContent.includes('No follower detected'),
+     $('sync_status_content').textContent);
+  setRole('follower');
+  await tick(20);
+  ok('choosing Follower shows Position', $('setting-display-sync_follower_position').style.display === '');
+
+  // ── sync: the poll runs only while on screen ────────────────────────────
+  let polls = syncPolls();
+  fireIntervals();
+  await tick(20);
+  ok('each interval tick polls once', syncPolls() === polls + 1, syncPolls() - polls);
+  setTab('logs');
+  ok('switching to another tab clears the interval', intervals.size === 0, intervals.size);
+  polls = syncPolls();
+  setTab('display');
+  await tick(20);
+  ok('switching back polls at once', syncPolls() === polls + 1 && intervals.size === 1, [syncPolls() - polls, intervals.size]);
+  setHidden(true);
+  ok('hiding the browser tab clears the interval', intervals.size === 0, intervals.size);
+  polls = syncPolls();
+  setHidden(false);
+  await tick(20);
+  ok('showing it polls at once', syncPolls() === polls + 1 && intervals.size === 1, [syncPolls() - polls, intervals.size]);
+
+  // ── sync: states ────────────────────────────────────────────────────────
+  async function poll() { fireIntervals(); await tick(20); return $('sync_status_content').textContent; }
+  syncAnswer = { status: 'success', data: { role: 'leader', state: 'connected', peer_ip: HOSTILE, peer_chain: 2 } };
+  ok('a connected follower, its address as text', (await poll()).includes('Follower connected — ' + HOSTILE)
+     && !$('sync_status_content').querySelector('img'), $('sync_status_content').textContent);
+  syncAnswer = { status: 'success', data: { role: 'leader', state: 'incompatible', error: 'rows differ ' + HOSTILE } };
+  ok('incompatible panels show the reason as text', (await poll()).includes('incompatible')
+     && !$('sync_error_detail').classList.contains('hidden') && $('sync_error_text').textContent === 'rows differ ' + HOSTILE
+     && !$('sync_error_detail').querySelector('img'));
+  syncAnswer = { status: 'success', data: realSync.data };
+  ok('the real server\'s answer is drawn', (await poll()).length > 0, $('sync_status_content').textContent);
+  syncMode = 'network';
+  ok('a failed poll says unavailable', (await poll()).includes('Sync status unavailable'));
+  syncAnswer = { status: 'success', data: { role: 'follower', state: 'follower', leader_ip: '10.0.0.2' } };
+  syncMode = 'ok';
+  ok('receiving from a leader', (await poll()).includes('Receiving from leader — 10.0.0.2'));
+  syncMode = 'login';
+  ok('a login redirect draws nothing', (await poll()).includes('Receiving from leader'));
+  syncMode = 'ok';
+
+  // ── standalone stops asking ─────────────────────────────────────────────
+  setRole('standalone');
+  polls = syncPolls();
+  fireIntervals();
+  await tick(20);
+  ok('standalone hides the bar and the poll asks nothing',
+     $('sync_status_bar').classList.contains('hidden') && syncPolls() === polls, syncPolls() - polls);
+
+  // ── window.updateSyncUI ─────────────────────────────────────────────────
+  $('sync_role').value = 'leader';
+  polls = syncPolls();
+  displayPage.updateSyncUI();
+  await tick(20);
+  ok('updateSyncUI() applies the role and asks once',
+     !$('sync_status_bar').classList.contains('hidden') && syncPolls() === polls + 1, syncPolls() - polls);
+
+  // ── swapped out ─────────────────────────────────────────────────────────
+  await swap('<p>another tab</p>');
+  ok('nothing left mounted', registry.list().length === 0, registry.list().length);
+  ok('no interval left running', intervals.size === 0, intervals.size);
+  polls = syncPolls();
+  setTab('overview');
+  setTab('display');
+  setHidden(true);
+  setHidden(false);
+  await tick(20);
+  ok('a swapped-out page never polls again', syncPolls() === polls && intervals.size === 0, syncPolls() - polls);
+  const hintsGone = count('/api/v3/config/scroll-speed-advice');
+  await swap();
+  $('vegas_scroll_speed').value = '40';
+  fire($('vegas_scroll_speed'), 'input');
+  await swap('<p>another tab</p>');
+  await tick(250);
+  ok('a hint still waiting out its debounce at the swap is never asked for',
+     count('/api/v3/config/scroll-speed-advice') === hintsGone, count('/api/v3/config/scroll-speed-advice') - hintsGone);
+
+  // ── the widget loads late ───────────────────────────────────────────────
+  delete window.PluginOrderList;
+  const beforeLate = count('/api/v3/plugins/installed');
+  await swap();
+  ok('no list request while the widget is missing', count('/api/v3/plugins/installed') === beforeLate);
+  window.PluginOrderList = widget;
+  await tick(150);
+  ok('the list starts once the widget arrives', count('/api/v3/plugins/installed') === beforeLate + 1);
+  delete window.PluginOrderList;
+  await swap();
+  const beforeGone = count('/api/v3/plugins/installed');
+  await swap('<p>another tab</p>');
+  window.PluginOrderList = widget;
+  await tick(250);
+  ok('a page swapped away while waiting starts nothing', count('/api/v3/plugins/installed') === beforeGone);
+
+  ok('no console errors', logged.length === 0, logged);
+  ok('no DOM errors', errs.length === 0, errs);
+
+  console.log(`\n${pass} passed, ${fail} failed`);
+  process.exit(fail ? 1 : 0);
+})().catch(e => { console.error(e); process.exit(1); });

test/js/dom/test_general_page.js

@@ -0,0 +1,272 @@
+// The General tab as a page module (static/v3/js/pages/general.js), in a real
+// DOM (jsdom) with the real server-rendered partial, the real timezone
+// widget and the real web-login endpoints' answer shapes. Built like
+// test_cache_page.js:
+//
+//   * the partial ships no <script> and no inline handlers; its root is
+//     data-page="general" and the Security section's forms and buttons name
+//     an action
+//   * the timezone picker is drawn once per swap-in, with the saved zone
+//   * after five swaps, each Security action makes exactly one request
+//   * a login change is a write: a swap does not cancel it, its result is
+//     still reported, and nothing is drawn into the page that has gone
+//   * token names reach the page as text
+//   * the settings form itself is left to htmx
+//   * window.webLogin's entry points still work
+const http = require('http');
+const fs = require('fs');
+const path = require('path');
+const { pathToFileURL } = require('url');
+const { JSDOM, VirtualConsole } = require('jsdom');
+
+const BASE = process.env.BASE || 'http://localhost:5000';
+const JS = path.resolve(__dirname, '../../../web_interface/static/v3/js');
+const get = p => new Promise((res, rej) =>
+  http.get(BASE + p, r => { let d = ''; r.on('data', c => d += c); r.on('end', () => res(d)); }).on('error', rej));
+const load = f => import(pathToFileURL(path.join(JS, f)).href);
+const tick = ms => new Promise(r => setTimeout(r, ms || 0));
+
+let pass = 0, fail = 0;
+const ok = (l, c, x) => c ? (pass++, console.log('  ok   ' + l))
+  : (fail++, console.log('  FAIL ' + l + (x !== undefined ? '  -> ' + JSON.stringify(x).slice(0, 300) : '')));
+
+(async () => {
+  const partial = await get('/partials/general');
+  const realTokens = JSON.parse(await get('/api/v3/auth/tokens'));
+  const { createRegistry } = await load('core/registry.js');
+  const { createApi } = await load('core/api.js');
+  const generalPage = await load('pages/general.js');
+
+  console.log('\n── General tab: page module (real DOM) ──');
+  ok('the partial ships no inline script', !/<script/i.test(partial));
+  ok('the partial has no inline click or submit handlers', !/\son(click|submit|input)=/i.test(partial));
+  ok('the partial root is data-page="general"', /data-page="general"/.test(partial));
+  const security = /id="web-login-settings"/.test(partial);
+  ok('the server renders the Security section (it has a login store)', security);
+  ok('the real token list answers in the shape the section shows',
+     realTokens.status === 'success' && realTokens.data && Array.isArray(realTokens.data.tokens), realTokens);
+  ok('the Security forms name their action',
+     /<form[^>]*data-action="set-password"/.test(partial) && /<form[^>]*data-action="create-token"/.test(partial));
+  ok('the Copy button names its action', /data-action="copy-token"/.test(partial));
+
+  const errs = [];
+  const logged = [];
+  const vc = new VirtualConsole();
+  vc.on('jsdomError', e => errs.push(String(e.message || e).split('\n')[0]));
+  vc.on('error', (...a) => logged.push(a.join(' ')));
+  const dom = new JSDOM(`<!doctype html><html><body><div id="general-content">${partial}</div></body></html>`,
+    { url: BASE + '/', virtualConsole: vc, runScripts: 'outside-only' });
+  const { window } = dom;
+  const doc = window.document;
+  const panel = doc.getElementById('general-content');
+  require('../led_escape').install(window);
+  window.eval(fs.readFileSync(path.join(JS, 'widgets/registry.js'), 'utf8'));
+  window.eval(fs.readFileSync(path.join(JS, 'widgets/timezone-selector.js'), 'utf8'));
+  const widgets = window.LEDMatrixWidgets;
+  ok('the widget scripts register timezone-selector', !!(widgets && widgets.get('timezone-selector')));
+
+  let confirmAnswer = true;
+  const confirms = [];
+  window.confirm = m => { confirms.push(m); return confirmAnswer; };
+  const reloads = [];
+  window.htmx = { ajax: (method, url, opts) => reloads.push([method, url, opts.target]) };
+
+  const HOSTILE = '<img src=x onerror="window.pwned=1">';
+  let mode = 'ok';
+  let nextId = 1;
+  const requests = [];
+  const pending = [];
+  function fakeFetch(url, init) {
+    requests.push({ url, method: init.method, body: init.body ? JSON.parse(init.body) : undefined });
+    const respond = (status, body, headers) => Promise.resolve({
+      status, ok: status >= 200 && status < 300,
+      headers: { get: h => (headers || {})[h] || null },
+      text: () => Promise.resolve(JSON.stringify(body)),
+    });
+    if (mode === 'network') return Promise.reject(new TypeError('Failed to fetch'));
+    if (mode === 'login') return respond(401, { status: 'error' }, { 'X-LEDMatrix-Login': '/login' });
+    if (mode === 'refuse') return respond(400, { status: 'error', message: 'Give the token a name.' });
+    if (url === '/api/v3/auth/tokens' && init.method === 'POST') {
+      const id = 'tok' + (nextId++);
+      const name = JSON.parse(init.body).name;
+      const answer = () => respond(201, {
+        status: 'success', message: 'Token created. Copy it now: it is not shown again.',
+        data: { token: 'lmx_' + id, record: { id, name, prefix: 'lmx_' + id.slice(0, 3), created_at: '2026-10-04T00:00:00' } },
+      });
+      if (mode === 'hang') return new Promise(resolve => pending.push(() => resolve(answer())));
+      return answer();
+    }
+    if (url.startsWith('/api/v3/auth/tokens/') && init.method === 'DELETE') {
+      return respond(200, { status: 'success', message: 'Token revoked.', data: { tokens: [] } });
+    }
+    if (url === '/api/v3/auth/password') {
+      return respond(200, { status: 'success', message: 'Login is on. Other browsers now need the password.' });
+    }
+    return respond(404, { status: 'error', message: 'unexpected ' + url });
+  }
+  const notes = [];
+  const registry = createRegistry({
+    document: doc,
+    context: { api: createApi({ fetch: fakeFetch }), notify: (m, t) => notes.push([m, t]) },
+  });
+  registry.register('general', generalPage);
+
+  const $ = id => doc.getElementById(id);
+  const root = () => doc.querySelector('[data-page="general"]');
+  const timezoneWidgets = () => $('timezone_container').querySelectorAll('.timezone-selector-widget').length;
+  const rows = () => doc.querySelectorAll('#web-login-tokens [data-token-id]');
+  const calls = (method, prefix) => requests.filter(r => r.method === method && r.url.startsWith(prefix));
+  const lastNote = () => notes[notes.length - 1] || [];
+  function submit(form) {
+    const event = new window.Event('submit', { bubbles: true, cancelable: true });
+    form.dispatchEvent(event);
+    return event;
+  }
+  const form = action => root().querySelector(`form[data-action="${action}"]`);
+  async function swap(html) {
+    panel.dispatchEvent(new window.CustomEvent('htmx:beforeSwap', { bubbles: true, detail: { target: panel, shouldSwap: true } }));
+    panel.innerHTML = html === undefined ? partial : html;
+    panel.dispatchEvent(new window.CustomEvent('htmx:afterSwap', { bubbles: true, detail: { target: panel } }));
+    await tick(20);
+  }
+
+  await registry.start();
+  await tick(20);
+
+  // ── the timezone picker ─────────────────────────────────────────────────
+  const savedZone = $('timezone_container').dataset.timezone;
+  ok('the partial carries the saved timezone', !!savedZone, savedZone);
+  ok('the timezone picker is drawn once', timezoneWidgets() === 1, timezoneWidgets());
+  ok('...holding the saved zone', $('timezone_data') && $('timezone_data').value === savedZone,
+     $('timezone_data') && $('timezone_data').value);
+  ok('...posted as "timezone"', $('timezone_data') && $('timezone_data').name === 'timezone');
+
+  for (let i = 0; i < 5; i++) await swap();
+  ok('one mounted page after five swaps', registry.list().length === 1, registry.list().length);
+  ok('the timezone picker is drawn once, not stacked', timezoneWidgets() === 1, timezoneWidgets());
+
+  // ── the settings form is htmx's ─────────────────────────────────────────
+  const settings = root().querySelector('form[hx-post="/api/v3/config/main"]');
+  ok('submitting the settings form is not prevented', settings && !submit(settings).defaultPrevented);
+  ok('...and makes no request of the page\'s own', requests.length === 0, requests.length);
+
+  if (security) {
+    // ── create a token ────────────────────────────────────────────────────
+    const before = rows().length;
+    const create = form('create-token');
+    create.querySelector('[name="name"]').value = HOSTILE;
+    create.setAttribute('data-dirty', '');
+    ok('Create token is handled by the page', submit(create).defaultPrevented);
+    await tick(20);
+    ok('one POST to /api/v3/auth/tokens', calls('POST', '/api/v3/auth/tokens').length === 1, requests);
+    ok('...with the name typed', calls('POST', '/api/v3/auth/tokens')[0].body.name === HOSTILE);
+    ok('a row is added', rows().length === before + 1, rows().length);
+    ok('the hostile token name is shown as text', root().querySelector('#web-login-tokens').textContent.includes(HOSTILE));
+    ok('...and created no element', !root().querySelector('#web-login-tokens img') && !window.pwned);
+    ok('the "No tokens yet" line is gone', !root().querySelector('#web-login-tokens [data-empty]'));
+    ok('the token is shown once', $('web-login-new-token-value').textContent === 'lmx_tok1'
+       && !$('web-login-new-token').classList.contains('hidden'));
+    ok('the form is clean again (no "Leave site?")', !create.hasAttribute('data-dirty'));
+    ok('one success notification', lastNote()[1] === 'success' && /Token created/.test(lastNote()[0]), notes);
+
+    // ── copy it (plain http: not a secure context, so it is selected) ────
+    root().querySelector('button[data-action="copy-token"]').click();
+    ok('Copy selects the token where the clipboard API is unavailable',
+       window.getSelection().toString() === 'lmx_tok1' && /Selected/.test(lastNote()[0]), lastNote());
+
+    // ── revoke it (the row drawn by the page, so delegation covers it) ───
+    confirmAnswer = false;
+    const added = rows()[rows().length - 1];
+    added.querySelector('button[data-action="revoke-token"]').click();
+    await tick(20);
+    ok('a cancelled Revoke sends nothing', calls('DELETE', '/api/v3/auth/tokens/').length === 0);
+    ok('...after asking with the token name as written', confirms.length === 1 && confirms[0].includes(HOSTILE), confirms);
+    confirmAnswer = true;
+    added.querySelector('button[data-action="revoke-token"]').click();
+    await tick(20);
+    ok('Revoke sends one DELETE for that token',
+       calls('DELETE', '/api/v3/auth/tokens/').length === 1 && calls('DELETE', '/api/v3/auth/tokens/')[0].url === '/api/v3/auth/tokens/tok1',
+       calls('DELETE', '/api/v3/auth/tokens/'));
+    ok('...and removes its row', rows().length === before, rows().length);
+
+    // ── the password ──────────────────────────────────────────────────────
+    const pw = form('set-password');
+    pw.querySelector('[name="new_password"]').value = 'correct horse battery';
+    pw.querySelector('[name="confirm_password"]').value = 'correct horse batterY';
+    submit(pw);
+    await tick(20);
+    ok('mismatched passwords are never sent', calls('POST', '/api/v3/auth/password').length === 0);
+    ok('...and say so', lastNote()[1] === 'error' && /do not match/.test(lastNote()[0]), lastNote());
+    pw.querySelector('[name="confirm_password"]').value = 'correct horse battery';
+    submit(pw);
+    await tick(20);
+    const sent = calls('POST', '/api/v3/auth/password');
+    ok('a matching password is sent once', sent.length === 1, sent.length);
+    ok('...with the current password only when the form has one',
+       sent[0] && sent[0].body.new_password === 'correct horse battery'
+         && (('current_password' in sent[0].body) === !!pw.querySelector('[name="current_password"]')), sent[0]);
+    ok('...and the section is reloaded once', reloads.length === 1 && reloads[0][1] === '/v3/partials/general'
+       && reloads[0][2] === '#general-content', reloads);
+
+    // ── refused, network failure, login redirect ──────────────────────────
+    mode = 'refuse';
+    submit(form('create-token'));
+    await tick(20);
+    ok('a refused request shows the server message', lastNote()[1] === 'error' && lastNote()[0] === 'Give the token a name.', lastNote());
+    mode = 'network';
+    submit(form('create-token'));
+    await tick(20);
+    ok('a network failure says the request failed', lastNote()[1] === 'error' && /^Request failed: /.test(lastNote()[0]), lastNote());
+    mode = 'login';
+    const quiet = notes.length;
+    submit(form('create-token'));
+    await tick(20);
+    ok('the login redirect shows nothing (the page is leaving)', notes.length === quiet, notes.slice(quiet));
+
+    // ── a write survives a swap ───────────────────────────────────────────
+    mode = 'hang';
+    await swap();
+    const rowsBefore = rows().length;
+    form('create-token').querySelector('[name="name"]').value = 'Late';
+    submit(form('create-token'));
+    await tick(5);
+    await swap();
+    pending.shift()();
+    await tick(20);
+    ok('a token created before a swap is still reported', lastNote()[1] === 'success', lastNote());
+    ok('...and draws nothing into the new page', rows().length === rowsBefore
+       && $('web-login-new-token').classList.contains('hidden'), rows().length);
+    mode = 'ok';
+
+    // ── window.webLogin ────────────────────────────────────────────────────
+    const viaAlias = calls('POST', '/api/v3/auth/tokens').length;
+    form('create-token').querySelector('[name="name"]').value = 'Alias';
+    await generalPage.webLogin.createToken(form('create-token'));
+    ok('webLogin.createToken(form) creates one token', calls('POST', '/api/v3/auth/tokens').length === viaAlias + 1);
+    ok('webLogin has the five old methods',
+       ['setPassword', 'disable', 'createToken', 'copyToken', 'revoke'].every(m => typeof generalPage.webLogin[m] === 'function'));
+  }
+
+  // ── the widget loads late ───────────────────────────────────────────────
+  delete window.LEDMatrixWidgets;
+  await swap();
+  ok('nothing drawn while the widget is missing', timezoneWidgets() === 0, timezoneWidgets());
+  window.LEDMatrixWidgets = widgets;
+  await tick(150);
+  ok('drawn once the widget arrives', timezoneWidgets() === 1, timezoneWidgets());
+
+  delete window.LEDMatrixWidgets;
+  await swap();
+  const kept = root();
+  await swap('<p>another tab</p>');
+  window.LEDMatrixWidgets = widgets;
+  await tick(250);
+  ok('a page swapped away while waiting draws nothing', kept.querySelectorAll('.timezone-selector-widget').length === 0);
+  ok('nothing left mounted', registry.list().length === 0, registry.list().length);
+
+  ok('no console errors', logged.length === 0, logged);
+  ok('no DOM errors', errs.length === 0, errs);
+
+  console.log(`\n${pass} passed, ${fail} failed`);
+  process.exit(fail ? 1 : 0);
+})().catch(e => { console.error(e); process.exit(1); });

test/js/dom/test_schedule_page.js

@@ -0,0 +1,167 @@
+// The Schedule tab as a page module (static/v3/js/pages/schedule.js), in a
+// real DOM (jsdom) with the real server-rendered partial and the real
+// widget registry and schedule-picker widget. Built like test_cache_page.js:
+//
+//   * the partial ships no <script> and no inline handlers; its root is
+//     data-page="schedule" and carries both saved schedules as JSON
+//   * both pickers are drawn once per swap-in, from the saved config, however
+//     many swaps came first
+//   * each form's save is reported in exactly one notification (the forms
+//     are marked data-reports-result so app.js stays quiet)
+//   * the dim brightness label follows the slider
+//   * a widget that loads late is waited for, and a page swapped away while
+//     waiting draws nothing
+//   * the old globals' entry points still work
+const http = require('http');
+const fs = require('fs');
+const path = require('path');
+const { pathToFileURL } = require('url');
+const { JSDOM, VirtualConsole } = require('jsdom');
+
+const BASE = process.env.BASE || 'http://localhost:5000';
+const JS = path.resolve(__dirname, '../../../web_interface/static/v3/js');
+const get = p => new Promise((res, rej) =>
+  http.get(BASE + p, r => { let d = ''; r.on('data', c => d += c); r.on('end', () => res(d)); }).on('error', rej));
+const load = f => import(pathToFileURL(path.join(JS, f)).href);
+const tick = ms => new Promise(r => setTimeout(r, ms || 0));
+
+let pass = 0, fail = 0;
+const ok = (l, c, x) => c ? (pass++, console.log('  ok   ' + l))
+  : (fail++, console.log('  FAIL ' + l + (x !== undefined ? '  -> ' + JSON.stringify(x).slice(0, 300) : '')));
+
+(async () => {
+  const partial = await get('/partials/schedule');
+  const { createRegistry } = await load('core/registry.js');
+  const schedulePage = await load('pages/schedule.js');
+
+  console.log('\n── Schedule tab: page module (real DOM) ──');
+  ok('the partial ships no inline script', !/<script/i.test(partial));
+  ok('the partial has no inline handlers', !/\son(click|input|change|submit)=/i.test(partial));
+  ok('the forms carry no hx-on handler', !/hx-on/i.test(partial));
+  ok('the partial root is data-page="schedule"', /data-page="schedule"/.test(partial));
+  ok('both forms are marked data-reports-result',
+     (partial.match(/<form[^>]*data-reports-result/g) || []).length === 2);
+
+  const errs = [];
+  const logged = [];
+  const vc = new VirtualConsole();
+  vc.on('jsdomError', e => errs.push(String(e.message || e).split('\n')[0]));
+  vc.on('error', (...a) => logged.push(a.join(' ')));
+  const dom = new JSDOM(`<!doctype html><html><body><div id="schedule-content">${partial}</div></body></html>`,
+    { url: BASE + '/', virtualConsole: vc, runScripts: 'outside-only' });
+  const { window } = dom;
+  const doc = window.document;
+  const panel = doc.getElementById('schedule-content');
+  // base.html defines LEDEscape (app-early.js) before any tab loads; the
+  // widget escapes with it.
+  require('../led_escape').install(window);
+  window.eval(fs.readFileSync(path.join(JS, 'widgets/registry.js'), 'utf8'));
+  window.eval(fs.readFileSync(path.join(JS, 'widgets/schedule-picker.js'), 'utf8'));
+  const widgets = window.LEDMatrixWidgets;
+  ok('the widget scripts register schedule-picker', !!(widgets && widgets.get('schedule-picker')));
+
+  const notes = [];
+  const registry = createRegistry({
+    document: doc,
+    context: { api: null, notify: (m, t) => notes.push([m, t]) },
+  });
+  registry.register('schedule', schedulePage);
+
+  const $ = id => doc.getElementById(id);
+  const root = () => doc.querySelector('[data-page="schedule"]');
+  const saved = key => JSON.parse(root().dataset[key]);
+  const drawn = () => ['schedule_picker_container', 'dim_schedule_picker_container']
+    .map(id => $(id).querySelectorAll('.schedule-picker-widget').length);
+  async function swap(html) {
+    panel.dispatchEvent(new window.CustomEvent('htmx:beforeSwap', { bubbles: true, detail: { target: panel, shouldSwap: true } }));
+    panel.innerHTML = html === undefined ? partial : html;
+    panel.dispatchEvent(new window.CustomEvent('htmx:afterSwap', { bubbles: true, detail: { target: panel } }));
+    await tick(20);
+  }
+  function answer(formId, xhr) {
+    $(formId).dispatchEvent(new window.CustomEvent('htmx:afterRequest', {
+      bubbles: true, detail: { xhr, elt: $(formId), successful: xhr.status < 300 } }));
+  }
+
+  await registry.start();
+  await tick(20);
+
+  // ── first load ──────────────────────────────────────────────────────────
+  ok('both pickers drawn once', drawn().join() === '1,1', drawn());
+  const schedule = saved('scheduleConfig');
+  const dim = saved('dimScheduleConfig');
+  ok('the saved config reaches the page as JSON', schedule && typeof schedule === 'object' && dim && typeof dim === 'object');
+  const mode = cfg => cfg.mode ? cfg.mode.replace('-', '_') : (cfg.days ? 'per_day' : 'global');
+  ok('the display picker shows the saved mode', $('schedule_mode_value').value === mode(schedule),
+     [$('schedule_mode_value').value, schedule.mode]);
+  ok('the dim picker shows the saved mode', $('dim_schedule_mode_value').value === mode(dim),
+     [$('dim_schedule_mode_value').value, dim.mode]);
+  ok('the dim picker shows the saved start time',
+     $('dim_schedule_start_time_hidden').value === (dim.start_time || '20:00'), $('dim_schedule_start_time_hidden').value);
+
+  // ── repeated swaps ──────────────────────────────────────────────────────
+  for (let i = 0; i < 5; i++) await swap();
+  ok('one mounted page after five swaps', registry.list().length === 1, registry.list().length);
+  ok('each picker drawn once, not stacked', drawn().join() === '1,1', drawn());
+
+  const okXhr = body => ({ status: 200, responseText: JSON.stringify(body) });
+  answer('schedule_form', okXhr({ status: 'success', message: 'Schedule configuration saved successfully' }));
+  ok('a schedule save is reported once', notes.length === 1, notes);
+  ok('...with the server message and status',
+     notes[0] && notes[0][0] === 'Schedule configuration saved successfully' && notes[0][1] === 'success', notes[0]);
+  answer('dim_schedule_form', okXhr({ status: 'success' }));
+  ok('a dim schedule save without a message says so',
+     notes.length === 2 && notes[1][0] === 'Dim schedule settings saved' && notes[1][1] === 'success', notes[1]);
+  answer('schedule_form', { status: 400, responseText: JSON.stringify({ status: 'error' }) });
+  ok('a refused save without a message says so',
+     notes.length === 3 && notes[2][0] === 'Error saving schedule' && notes[2][1] === 'error', notes[2]);
+  answer('dim_schedule_form', { status: 502, responseText: '<html>Bad gateway</html>' });
+  ok('a non-JSON answer is an error',
+     notes.length === 4 && notes[3][0] === 'Invalid response from server' && notes[3][1] === 'error', notes[3]);
+  answer('schedule_form', { status: 200, responseText: 'null' });
+  ok('a JSON null answer is an error, not a crash',
+     notes.length === 5 && notes[4][1] === 'error', notes[4]);
+  // An htmx request from elsewhere on the page (outside both forms) is not a save.
+  root().querySelector('.settings-filter').dispatchEvent(new window.CustomEvent('htmx:afterRequest', {
+    bubbles: true, detail: { xhr: okXhr({ status: 'success', message: 'x' }) } }));
+  ok('a request from outside the two forms reports nothing', notes.length === 5, notes.length);
+
+  // ── the brightness label ────────────────────────────────────────────────
+  $('dim_brightness').value = '42';
+  $('dim_brightness').dispatchEvent(new window.Event('input', { bubbles: true }));
+  ok('the dim brightness label follows the slider', $('dim_brightness_display').textContent === '42%',
+     $('dim_brightness_display').textContent);
+
+  // ── the widget loads late ───────────────────────────────────────────────
+  delete window.LEDMatrixWidgets;
+  await swap();
+  ok('nothing drawn while the widget is missing', drawn().join() === '0,0', drawn());
+  window.LEDMatrixWidgets = widgets;
+  await tick(150);
+  ok('drawn once the widget arrives', drawn().join() === '1,1', drawn());
+
+  delete window.LEDMatrixWidgets;
+  await swap();
+  const kept = root();
+  await swap('<p>another tab</p>');
+  window.LEDMatrixWidgets = widgets;
+  await tick(250);
+  ok('a page swapped away while waiting draws nothing',
+     kept.querySelectorAll('.schedule-picker-widget').length === 0);
+  ok('nothing left mounted', registry.list().length === 0, registry.list().length);
+
+  // ── the old globals ─────────────────────────────────────────────────────
+  await swap();
+  const before = notes.length;
+  schedulePage.handleScheduleResponse({ target: $('schedule_form'), detail: { xhr: okXhr({ status: 'success' }) } });
+  schedulePage.handleDimScheduleResponse({ target: $('dim_schedule_form'), detail: { xhr: okXhr({ status: 'success' }) } });
+  ok('handleScheduleResponse(event) and handleDimScheduleResponse(event) report once each',
+     notes.length === before + 2 && notes[before][0] === 'Schedule settings saved'
+       && notes[before + 1][0] === 'Dim schedule settings saved', notes.slice(before));
+
+  ok('no console errors', logged.length === 0, logged);
+  ok('no DOM errors', errs.length === 0, errs);
+
+  console.log(`\n${pass} passed, ${fail} failed`);
+  process.exit(fail ? 1 : 0);
+})().catch(e => { console.error(e); process.exit(1); });

test/js/dom/test_visibility_service.js

@@ -0,0 +1,211 @@
+// The page-visibility service (static/v3/js/core/visibility.js), in a real
+// DOM (jsdom) with the real window.LEDVisibility from app-shell.js and the
+// real page registry, wired the way core/boot.js wires them (each mount gets
+// ctx.visibility from mountContext):
+//
+//   * whileVisible(start, stop) runs start() only while the page's tab is the
+//     active tab AND the browser tab is visible, stop() when either changes
+//   * every(ms, fn) calls fn at once and then on an interval while visible;
+//     no interval is left running while hidden
+//   * everything a page registered stops when the page is swapped out, and a
+//     page that registers after it was destroyed starts nothing
+//   * registrations never replace each other (two timers on one page, two
+//     pages, or a classic partial's own LEDVisibility key)
+//   * without LEDVisibility, the browser tab's visibility alone decides
+//
+// Needs jsdom but no server.
+const fs = require('fs');
+const path = require('path');
+const { pathToFileURL } = require('url');
+const { JSDOM, VirtualConsole } = require('jsdom');
+
+const JS = path.resolve(__dirname, '../../../web_interface/static/v3/js');
+const load = f => import(pathToFileURL(path.join(JS, f)).href);
+const tick = ms => new Promise(r => setTimeout(r, ms || 0));
+
+let pass = 0, fail = 0;
+const ok = (l, c, x) => c ? (pass++, console.log('  ok   ' + l))
+  : (fail++, console.log('  FAIL ' + l + (x !== undefined ? '  -> ' + JSON.stringify(x).slice(0, 300) : '')));
+
+(async () => {
+  const { createRegistry } = await load('core/registry.js');
+  const { createVisibility } = await load('core/visibility.js');
+
+  console.log('\n── Page visibility service (real DOM, real LEDVisibility) ──');
+  const errs = [];
+  const logged = [];
+  const vc = new VirtualConsole();
+  vc.on('jsdomError', e => errs.push(String(e.message || e).split('\n')[0]));
+  vc.on('error', (...a) => logged.push(a.join(' ')));
+  const dom = new JSDOM('<!doctype html><html><body><div id="display-content"></div><div id="logs-content"></div></body></html>',
+    { url: 'http://localhost/', virtualConsole: vc, runScripts: 'outside-only' });
+  const { window } = dom;
+  const doc = window.document;
+
+  // The browser tab's visibility, under the test's control.
+  let hidden = false;
+  Object.defineProperty(doc, 'hidden', { get: () => hidden, configurable: true });
+  function setHidden(value) {
+    hidden = value;
+    doc.dispatchEvent(new window.Event('visibilitychange'));
+  }
+  function setTab(tab) {
+    doc.dispatchEvent(new window.CustomEvent('ledmatrix:tab-changed', { detail: { tab } }));
+  }
+
+  // Intervals, counted: the point is that none is left running.
+  const intervals = new Map();
+  let nextInterval = 1;
+  window.setInterval = (fn, ms) => { const id = nextInterval++; intervals.set(id, { fn, ms }); return id; };
+  window.clearInterval = id => { intervals.delete(id); };
+  const fireIntervals = () => [...intervals.values()].forEach(i => i.fn());
+
+  // The real LEDVisibility (app-shell.js). Alpine is absent, so the active
+  // tab is the last ledmatrix:tab-changed. The SSE streams are not under
+  // test: they open stand-in EventSources.
+  window.getApp = () => null;
+  window.EventSource = class { addEventListener() {} removeEventListener() {} close() {} };
+  window.eval(fs.readFileSync(path.join(JS, 'app-shell.js'), 'utf8'));
+  ok('app-shell.js defines LEDVisibility', !!(window.LEDVisibility && window.LEDVisibility.onActive));
+
+  const visibility = createVisibility({ window });
+  const registry = createRegistry({
+    document: doc,
+    context: {},
+    mountContext: ctx => ({ visibility: visibility.forPage(ctx) }),
+  });
+
+  const log = [];
+  let polls = 0;
+  const handles = [];
+  registry.register('display', {
+    init(root, ctx) {
+      handles.push(ctx.visibility);
+      ctx.visibility.whileVisible(() => log.push('start'), () => log.push('stop'));
+      ctx.visibility.every(5000, () => { polls++; });
+    },
+  });
+  let otherRuns = 0;
+  registry.register('logs', {
+    init(root, ctx) { ctx.visibility.every(1000, () => { otherRuns++; }); },
+  });
+
+  const panel = doc.getElementById('display-content');
+  async function swap(html) {
+    panel.dispatchEvent(new window.CustomEvent('htmx:beforeSwap', { bubbles: true, detail: { target: panel, shouldSwap: true } }));
+    panel.innerHTML = html;
+    panel.dispatchEvent(new window.CustomEvent('htmx:afterSwap', { bubbles: true, detail: { target: panel } }));
+    await tick(10);
+  }
+
+  // A classic partial's own registration, keyed by its tab name: the
+  // service's registrations must not replace it, nor it them.
+  let classic = 0;
+  window.LEDVisibility.onActive('display', () => { classic++; }, () => {});
+
+  setTab('overview');
+  await registry.start();
+  await swap('<div data-page="display"></div>');
+
+  // ── mounted on another tab ──────────────────────────────────────────────
+  ok('mounted while another tab is active: nothing starts', log.length === 0 && polls === 0, [log, polls]);
+  ok('...and no interval runs', intervals.size === 0, intervals.size);
+  ok('isVisible() is false', handles[0].isVisible() === false);
+  ok('the page\'s tab is its name', handles[0].tab === 'display');
+
+  // ── its tab comes on screen ─────────────────────────────────────────────
+  setTab('display');
+  ok('switching to the tab runs start()', log.join() === 'start', log);
+  ok('every() calls fn at once', polls === 1, polls);
+  ok('...and sets one interval at the asked period', intervals.size === 1 && [...intervals.values()][0].ms === 5000,
+     [...intervals.values()].map(i => i.ms));
+  ok('isVisible() is true', handles[0].isVisible() === true);
+  ok('the classic registration still runs alongside', classic === 1, classic);
+  fireIntervals();
+  fireIntervals();
+  ok('fn runs on each interval', polls === 3, polls);
+
+  // ── the browser tab is hidden, then shown ───────────────────────────────
+  setHidden(true);
+  ok('hiding the browser tab runs stop()', log.join() === 'start,stop', log);
+  ok('...and clears the interval', intervals.size === 0, intervals.size);
+  ok('isVisible() is false while hidden', handles[0].isVisible() === false);
+  setHidden(false);
+  ok('showing it again runs start()', log.join() === 'start,stop,start', log);
+  ok('...and fn at once, with one interval again', polls === 4 && intervals.size === 1, [polls, intervals.size]);
+
+  // ── another tab ─────────────────────────────────────────────────────────
+  setTab('logs');
+  ok('switching away runs stop() and clears the interval', log.join() === 'start,stop,start,stop' && intervals.size === 0,
+     [log, intervals.size]);
+  setTab('display');
+  ok('switching back restarts it', log.length === 5 && polls === 5 && intervals.size === 1, [log, polls]);
+
+  // ── the partial is swapped out while on screen ──────────────────────────
+  await swap('<p>no page here</p>');
+  ok('a swap-out stops it', log[log.length - 1] === 'stop', log);
+  ok('...and leaves no interval running', intervals.size === 0, intervals.size);
+  const before = [log.length, polls];
+  setTab('overview');
+  setTab('display');
+  setHidden(true);
+  setHidden(false);
+  ok('a destroyed page never starts again', log.length === before[0] && polls === before[1], [log, polls]);
+  ok('the classic registration keeps running after the swap', classic === 5, classic);
+
+  // ── five swaps, then one page ───────────────────────────────────────────
+  for (let i = 0; i < 5; i++) await swap('<div data-page="display"></div>');
+  ok('after five swaps one interval runs, not five', intervals.size === 1, intervals.size);
+  const pollsBefore = polls;
+  fireIntervals();
+  ok('...and one poll per tick', polls === pollsBefore + 1, polls - pollsBefore);
+
+  // ── two timers on one page, and an end function ─────────────────────────
+  const h = handles[handles.length - 1];
+  let a = 0, b = 0;
+  const endA = h.every(100, () => { a++; });
+  h.every(200, () => { b++; });
+  ok('two more timers on one page both start', a === 1 && b === 1 && intervals.size === 3, [a, b, intervals.size]);
+  endA();
+  endA();
+  ok('an end function stops just its own timer (twice is harmless)', intervals.size === 2, intervals.size);
+
+  // ── a page that registers after it was destroyed ────────────────────────
+  const gone = handles[handles.length - 1];
+  await swap('<p>gone</p>');
+  ok('the swap-out clears every timer the page had', intervals.size === 0, intervals.size);
+  let late = 0;
+  const end = gone.every(1000, () => { late++; });
+  ok('registering after destroy starts nothing', late === 0 && intervals.size === 0 && typeof end === 'function');
+
+  // ── a start() that throws ───────────────────────────────────────────────
+  await swap('<div data-page="display"></div>');
+  const h2 = handles[handles.length - 1];
+  const loggedBefore = logged.length;
+  let afterThrow = 0;
+  h2.whileVisible(() => { throw new Error('boom'); }, () => {});
+  h2.whileVisible(() => { afterThrow++; }, () => {});
+  ok('a throwing start() is logged', logged.length === loggedBefore + 1 && /boom|start failed/.test(logged.join()),
+     logged.slice(loggedBefore));
+  ok('...and the next registration still starts', afterThrow === 1);
+  await swap('<p>gone</p>');
+
+  // ── without LEDVisibility (a page outside base.html) ────────────────────
+  const bare = createVisibility({ window, tracker: () => null }).forPage({ name: 'standalone', signal: new window.AbortController().signal });
+  const seen = [];
+  bare.whileVisible(() => seen.push('start'), () => seen.push('stop'));
+  ok('without LEDVisibility, a visible document starts at once', seen.join() === 'start', seen);
+  setHidden(true);
+  ok('...and hiding it stops', seen.join() === 'start,stop', seen);
+  ok('...isVisible() follows the document', bare.isVisible() === false);
+  setHidden(false);
+  ok('...and showing it starts again', seen.join() === 'start,stop,start', seen);
+
+  ok('registrations need functions', (() => { try { h2.whileVisible(null, null); return false; } catch { return true; } })());
+  ok('every() needs a positive period', (() => { try { h2.every(0, () => {}); return false; } catch { return true; } })());
+  ok('the logs page was never on screen: it never ran', otherRuns === 0, otherRuns);
+  ok('no DOM errors', errs.length === 0, errs);
+
+  console.log(`\n${pass} passed, ${fail} failed`);
+  process.exit(fail ? 1 : 0);
+})().catch(e => { console.error(e); process.exit(1); });

test/js/run_all.js

@@ -36,7 +36,9 @@ const UNIT = ['unit/test_list_filter.js', 'unit/test_render_cards.js',
 const DOM = ['dom/test_installed_dom.js', 'dom/test_store_dom.js', 'dom/test_no_double_fetch.js',
              'dom/test_tools_sections.js', 'dom/test_cache_page.js',
              'dom/test_durations_page.js', 'dom/test_operation_history_page.js',
-             'dom/test_raw_json_page.js', 'dom/test_backup_restore_page.js'];
+             'dom/test_raw_json_page.js', 'dom/test_backup_restore_page.js',
+             'dom/test_schedule_page.js', 'dom/test_general_page.js',
+             'dom/test_visibility_service.js', 'dom/test_display_page.js'];
 
 function reachable(url) {
   return new Promise(res => {

test/js/unit/test_display_partial_ids.js

@@ -1,21 +1,22 @@
-// The Display tab's inline script must only look up elements the partial
+// The Display tab's page module must only look up elements the partial
 // renders.
 //
-// Its brightness slider handler also wrote to #brightness-display, a "LED
-// brightness: N%" line that #387 removed from partials/display.html. The
+// Its brightness slider handler once also wrote to #brightness-display, a
+// "LED brightness: N%" line that #387 removed from partials/display.html. The
 // lookup returned null, so every movement of the slider threw a TypeError.
-// This checks every literal getElementById() in the partial's inline scripts
-// against the ids its markup renders, and runs the shipped script in a vm
-// with a fake DOM (null for an id the markup lacks, as in a browser) to move
-// the slider.
+// This imports the shipped module (static/v3/js/pages/display.js), starts it
+// on a fake root that answers only for the ids the partial's markup renders
+// (null for any other, as in a browser), fires every listener it registered,
+// and checks that every id it asked for exists. Then it moves the slider.
 //
 // No jsdom and no server needed.
 
 const fs = require('fs');
 const path = require('path');
-const vm = require('vm');
+const { pathToFileURL } = require('url');
 
 const PARTIAL = path.resolve(__dirname, '../../../web_interface/templates/v3/partials/display.html');
+const JS = path.resolve(__dirname, '../../../web_interface/static/v3/js');
 
 let pass = 0, fail = 0;
 const ok = (label, cond, extra) => cond
@@ -23,86 +24,93 @@ const ok = (label, cond, extra) => cond
   : (fail++, console.log('  FAIL ' + label + (extra !== undefined ? '  ' + JSON.stringify(extra) : '')));
 
 const html = fs.readFileSync(PARTIAL, 'utf8');
-const blocks = [...html.matchAll(/<script\b[^>]*>([\s\S]*?)<\/script[^>]*>/gi)];
-const scripts = blocks.map(m => m[1]);
-// The markup is what lies between the script blocks (sliced around them, not
-// a replace(), which CodeQL reads as an incomplete HTML sanitizer).
-let markup = '';
-let from = 0;
-for (const m of blocks) {
-  markup += html.slice(from, m.index);
-  from = m.index + m[0].length;
-}
-markup += html.slice(from);
-const rendered = new Set([...markup.matchAll(/\bid="([^"{}]+)"/g)].map(m => m[1]));
+const rendered = new Set([...html.matchAll(/\bid="([^"{}]+)"/g)].map(m => m[1]));
 
-console.log('\n── Display partial: element lookups ──');
-
-// 1. Static: every literal lookup names an id the partial renders.
-const lookups = scripts.flatMap(s => [...s.matchAll(/getElementById\('([^']+)'\)/g)].map(m => m[1]));
-const missing = [...new Set(lookups.filter(id => !rendered.has(id)))];
-ok('the inline scripts look elements up', lookups.length > 0, lookups.length);
-ok('every looked-up id is rendered by the partial', missing.length === 0, missing);
-
-// 2. Behaviour: moving the brightness slider updates its label and throws nothing.
 function fakeElement(id) {
   const listeners = {};
   const classes = new Set();
   return {
-    id, value: '', textContent: '', min: '', max: '', checked: false,
+    id, value: '1', textContent: '', min: '', max: '', checked: false,
     style: {}, dataset: {}, className: '',
     classList: {
       add: c => classes.add(c), remove: c => classes.delete(c),
-      toggle: (c, on) => (on === undefined ? (classes.has(c) ? classes.delete(c) : classes.add(c)) : (on ? classes.add(c) : classes.delete(c))),
       contains: c => classes.has(c),
     },
     addEventListener: (type, fn) => { (listeners[type] ||= []).push(fn); },
     dispatchEvent() { return true; },
     appendChild() {},
+    getAttribute: () => null,
     listeners,
   };
 }
 
-const main = scripts.find(s => s.includes("getElementById('brightness')"));
-ok('found the script that wires the brightness slider', !!main);
-if (main) {
-  const elements = new Map();
-  const document = {
-    readyState: 'complete',
-    hidden: false,
-    getElementById: id => {
-      if (!rendered.has(id)) return null;
-      if (!elements.has(id)) elements.set(id, fakeElement(id));
-      return elements.get(id);
-    },
-    createElement: () => fakeElement(''),
-    createTextNode: () => ({}),
-    addEventListener() {},
-  };
-  const window = {
-    LEDEscape: { html: v => String(v), attr: v => String(v) },
-    LEDVisibility: { onActive() {} },
-  };
-  const context = {
-    window, document, console, URLSearchParams,
-    fetch: () => new Promise(() => {}),
-    setTimeout: () => 0, clearTimeout() {}, setInterval: () => 0, clearInterval() {},
-  };
-  vm.createContext(context);
-  let loadError = null;
-  try { vm.runInContext(main, context); } catch (e) { loadError = e; }
-  ok('the script loads', !loadError, loadError && String(loadError));
+(async () => {
+  console.log('\n── Display page module: element lookups ──');
+  const display = await import(pathToFileURL(path.join(JS, 'pages/display.js')).href);
 
-  const slider = elements.get('brightness');
-  const handlers = (slider && slider.listeners.input) || [];
-  ok('the slider has an input handler', handlers.length > 0);
+  const asked = new Set();
+  const elements = new Map();
+  const timers = [];
+  const win = {
+    setTimeout: fn => { timers.push(fn); return timers.length; },
+    clearTimeout() {},
+    URLSearchParams,
+    Event: class { constructor(type) { this.type = type; } },
+    PluginOrderList: { init() {} },
+  };
+  const doc = { defaultView: win, createElement: () => fakeElement(''), createTextNode: () => ({}) };
+  const rootListeners = {};
+  const root = {
+    ownerDocument: doc,
+    querySelector(sel) {
+      const m = /^#([\w-]+)$/.exec(sel);
+      if (!m) throw new Error('unexpected selector ' + sel);
+      asked.add(m[1]);
+      if (!rendered.has(m[1])) return null;
+      if (!elements.has(m[1])) elements.set(m[1], fakeElement(m[1]));
+      return elements.get(m[1]);
+    },
+    addEventListener: (type, fn) => { (rootListeners[type] ||= []).push(fn); },
+    contains: () => true,
+  };
+  const never = () => new Promise(() => {});
+  const polls = [];
+  const ctx = {
+    root, name: 'display', state: {}, signal: { aborted: false },
+    api: { get: never },
+    visibility: { every: (ms, fn) => { polls.push(ms); fn(); return () => {}; } },
+  };
+
+  let loadError = null;
+  try { display.init(root, ctx); } catch (e) { loadError = e; }
+  ok('init() runs', !loadError, loadError && String(loadError));
+  ok('the sync status is polled through ctx.visibility', polls.length === 1 && polls[0] === 5000, polls);
+
+  // Fire everything it wired, so every lookup it can make is made.
   let thrown = null;
+  try {
+    for (const el of elements.values()) {
+      for (const fns of Object.values(el.listeners)) fns.forEach(fn => fn.call(el, { target: el }));
+    }
+    while (timers.length) timers.shift()();
+  } catch (e) { thrown = e; }
+  ok('its listeners and timers run without throwing', !thrown, thrown && String(thrown));
+
+  const missing = [...asked].filter(id => !rendered.has(id));
+  ok('it looks elements up', asked.size > 10, asked.size);
+  ok('every looked-up id is rendered by the partial', missing.length === 0, missing);
+
+  const slider = elements.get('brightness') || fakeElement('brightness');
+  const handlers = slider.listeners.input || [];
+  ok('the slider has an input handler', handlers.length > 0);
   slider.value = '42';
+  thrown = null;
   try { handlers.forEach(fn => fn.call(slider, { target: slider })); } catch (e) { thrown = e; }
   ok('moving the slider throws nothing', !thrown, thrown && String(thrown));
-  ok('...and shows the new value', elements.get('brightness-value').textContent === '42',
-     elements.get('brightness-value').textContent);
-}
+  const label = elements.get('brightness-value');
+  ok('...and shows the new value', !!label && label.textContent === '42', label && label.textContent);
 
-console.log(`\n${pass} passed, ${fail} failed\n`);
-process.exit(fail ? 1 : 0);
+  display.destroy(root, ctx);
+  console.log(`\n${pass} passed, ${fail} failed\n`);
+  process.exit(fail ? 1 : 0);
+})().catch(e => { console.error(e); process.exit(1); });

test/js/unit/test_general_web_login_token.js

@@ -3,32 +3,24 @@
 // app.js marks a form data-dirty on any input in it and clears the mark only
 // after a successful htmx request; its beforeunload handler then asks "Leave
 // site?" while any visible form is still dirty. The token form posts with
-// fetch (window.webLogin.createToken in partials/general.html), so after a
-// token was created the form stayed dirty and reloading the page while the
-// General tab was open prompted about changes that had been saved.
+// fetch (createToken in static/v3/js/pages/general.js), so after a token was
+// created the form stayed dirty and reloading the page while the General tab
+// was open prompted about changes that had been saved.
 //
-// Runs the shipped inline script in a vm with a fake fetch and DOM -- no jsdom
-// and no server needed.
+// Imports the shipped page module and runs createToken with a fake fetch and
+// DOM -- no jsdom and no server needed.
 
-const fs = require('fs');
 const path = require('path');
-const vm = require('vm');
+const { pathToFileURL } = require('url');
 
-const PARTIAL = path.resolve(__dirname, '../../../web_interface/templates/v3/partials/general.html');
+const JS = path.resolve(__dirname, '../../../web_interface/static/v3/js');
+const load = f => import(pathToFileURL(path.join(JS, f)).href);
 
 let pass = 0, fail = 0;
 const ok = (label, cond, extra) => cond
   ? (pass++, console.log('  ok   ' + label))
   : (fail++, console.log('  FAIL ' + label + (extra !== undefined ? '  ' + JSON.stringify(extra) : '')));
 
-function webLoginScript() {
-  const html = fs.readFileSync(PARTIAL, 'utf8');
-  const scripts = [...html.matchAll(/<script\b[^>]*>([\s\S]*?)<\/script[^>]*>/gi)].map(m => m[1]);
-  const found = scripts.find(s => s.includes('window.webLogin = {'));
-  if (!found) throw new Error('webLogin script not found in general.html');
-  return found;
-}
-
 function el() {
   const classes = new Set(['hidden']);
   return {
@@ -38,29 +30,28 @@ function el() {
   };
 }
 
-function load(answer) {
+async function setup(answer) {
+  const { createApi } = await load('core/api.js');
+  const general = await load('pages/general.js');
   const elements = {
-    'web-login-tokens': el(),
-    'web-login-new-token-value': el(),
-    'web-login-new-token': el(),
+    '#web-login-tokens': el(),
+    '#web-login-new-token-value': el(),
+    '#web-login-new-token': el(),
   };
   const notes = [];
-  const window = { showNotification: (m, t) => notes.push([m, t]), alert() {}, confirm: () => true };
-  const context = {
-    window, console,
-    document: {
-      getElementById: id => elements[id] || null,
-      createElement: () => el(),
-      querySelectorAll: () => [],
-    },
-    fetch: () => Promise.resolve({
-      ok: answer.ok, status: answer.ok ? 200 : 400,
-      json: () => Promise.resolve(answer.body),
-    }),
+  const doc = { createElement: () => el(), defaultView: { confirm: () => true } };
+  const root = { ownerDocument: doc, querySelector: sel => elements[sel] || null, querySelectorAll: () => [] };
+  const fetch = () => Promise.resolve({
+    ok: answer.ok, status: answer.ok ? 200 : 400,
+    headers: { get: () => null },
+    text: () => Promise.resolve(JSON.stringify(answer.body)),
+  });
+  const ctx = {
+    root, state: {}, signal: { aborted: false },
+    api: createApi({ fetch }),
+    notify: (m, t) => notes.push([m, t]),
   };
-  vm.createContext(context);
-  vm.runInContext(webLoginScript(), context);
-  return { webLogin: context.window.webLogin, elements, notes };
+  return { general, ctx, elements, notes };
 }
 
 function dirtyForm() {
@@ -74,29 +65,25 @@ function dirtyForm() {
   };
 }
 
-const flush = async () => { for (let i = 0; i < 10; i++) await new Promise(r => setImmediate(r)); };
-
 (async () => {
   console.log('\n── General tab: API token form ──');
 
   {
-    const t = load({ ok: true, body: {
+    const t = await setup({ ok: true, body: {
       status: 'success', message: 'Token created',
       data: { token: 'lmx_secret', record: { id: 't1', name: 'Home Assistant', prefix: 'lmx_sec' } },
     } });
     const form = dirtyForm();
-    t.webLogin.createToken(form);
-    await flush();
-    ok('the new token is shown', t.elements['web-login-new-token-value'].textContent === 'lmx_secret');
+    await t.general.createToken(t.ctx, form);
+    ok('the new token is shown', t.elements['#web-login-new-token-value'].textContent === 'lmx_secret');
     ok('a created token leaves the form clean (no "Leave site?" on reload)',
        !form.hasAttribute('data-dirty'));
   }
 
   {
-    const t = load({ ok: false, body: { status: 'error', message: 'Name is required' } });
+    const t = await setup({ ok: false, body: { status: 'error', message: 'Name is required' } });
     const form = dirtyForm();
-    t.webLogin.createToken(form);
-    await flush();
+    await t.general.createToken(t.ctx, form);
     ok('a refused request reports the error', t.notes.some(([m, type]) => type === 'error' && /Name is required/.test(m)),
        t.notes);
     ok('...and keeps the form dirty: nothing was saved', form.hasAttribute('data-dirty'));

test/js/unit/test_html_escaping.js

@@ -103,17 +103,16 @@ const ESCAPERS = [
    'static/v3/js/widgets/text-input.js', 'function escapeHtml(text) {', 'escapeHtml', false],
   ['slider.js (escapeAttr)',
    'static/v3/js/widgets/slider.js', 'function escapeAttr(text) {', 'escapeAttr', false],
-  ['display.html (escapeAttr)',
-   'templates/v3/partials/display.html', 'function escapeAttr(text) {', 'escapeAttr', false],
   ['tools.html (escHtml)',
    'templates/v3/partials/tools.html', 'function escHtml(s) {', 'escHtml', false],
   ['tools.html (phEscape)',
    'templates/v3/partials/tools.html', 'function phEscape(s) {', 'phEscape', false],
   ['logs.html (escapeHtml)',
    'templates/v3/partials/logs.html', 'function escapeHtml(text) {', 'escapeHtml', false],
-  // cache.html, backup_restore.html and operation_history.html have no
-  // script any more: their js/pages/ modules draw server data with
-  // textContent, and each page's suite in test/js/dom/ checks a hostile value.
+  // cache.html, backup_restore.html, operation_history.html and display.html
+  // have no script any more (display.html's two escapers were never called):
+  // their js/pages/ modules draw server data with textContent, and each
+  // page's suite in test/js/dom/ checks a hostile value.
 ];
 
 // The breakout payload: closes a double-quoted attribute and opens an event

test/js/unit/test_page_registry.js

@@ -242,6 +242,46 @@ function recorder(log) {
     ok('has()', reg.has('dup') && !reg.has('nope'));
   }
 
+  console.log('\n10. mountContext adds per-mount fields, after the shared ones');
+  {
+    const doc = new Doc();
+    const panel = doc.body.appendChild(new El('div', { id: 'panel' }));
+    panel.appendChild(new El('div', { id: 'a', [PAGE_ATTRIBUTE]: 'demo' }));
+    const seen = [];
+    const made = [];
+    const reg = createRegistry({
+      document: doc, context: { api: 'shared' }, logger: quiet,
+      mountContext(ctx) {
+        made.push([ctx.name, ctx.root.getAttribute('id'), !!ctx.signal, ctx.api]);
+        return { bound: { root: ctx.root, signal: ctx.signal } };
+      },
+    });
+    reg.register('demo', { init(root, ctx) { seen.push(ctx); } });
+    await reg.start();
+    await tick();
+    ok('mountContext sees the mount\'s name, root, signal and the shared services',
+       made.length === 1 && made[0].join() === 'demo,a,true,shared', made);
+    ok('...and its fields reach init()', seen.length === 1 && seen[0].bound && seen[0].bound.root === seen[0].root, seen.length);
+    fire(panel, 'htmx:beforeSwap', { target: panel, shouldSwap: true });
+    panel.replaceChildren(new El('div', { id: 'b', [PAGE_ATTRIBUTE]: 'demo' }));
+    fire(panel, 'htmx:afterSwap', { target: panel });
+    await tick();
+    ok('called again for each new mount, with that mount\'s signal',
+       made.length === 2 && seen.length === 2 && !!seen[1].bound && seen[1].bound.signal === seen[1].signal
+         && seen[0].signal.aborted, made);
+
+    const errors = [];
+    const doc2 = new Doc();
+    doc2.body.appendChild(new El('div', { id: 'c', [PAGE_ATTRIBUTE]: 'demo' }));
+    const reg2 = createRegistry({ document: doc2, logger: { error: (...a) => errors.push(a.join(' ')) },
+                                  mountContext() { throw new Error('boom'); } });
+    let started = 0;
+    reg2.register('demo', { init() { started++; } });
+    await reg2.start();
+    await tick();
+    ok('a throwing mountContext is logged and the page still starts', started === 1 && errors.length === 1, errors);
+  }
+
   console.log(`\n${pass} passed, ${fail} failed`);
   process.exit(fail ? 1 : 0);
 })().catch(e => { console.error(e); process.exit(1); });

test/js/unit/test_restart_banner.js

@@ -19,7 +19,7 @@ const ok = (label, cond, extra) => cond
   ? (pass++, console.log('  ok   ' + label))
   : (fail++, console.log('  FAIL ' + label + (extra !== undefined ? '  ' + JSON.stringify(extra) : '')));
 
-function load() {
+function load(notes) {
   const handlers = {};
   const listen = (target) => (type, fn) => { (handlers[target + ':' + type] ||= []).push(fn); };
   const banner = { style: { display: 'none' } };
@@ -43,14 +43,18 @@ function load() {
       removeItem: (k) => { delete store[k]; },
       getItem: (k) => (k in store ? store[k] : null),
     },
-    showNotification: () => {},
+    showNotification: (m, t) => { if (notes) notes.push([m, t]); },
     setTimeout: () => 0,
   };
   vm.createContext(context);
   vm.runInContext(fs.readFileSync(path.join(V3, 'app.js'), 'utf8'), context);
   const afterRequest = (handlers['body:htmx:afterRequest'] || [])[0];
-  const fire = ({ status = 200, body, path: reqPath = '/api/v3/anything', reportsItself = false }) => {
-    const elt = { closest: () => (reportsItself ? {} : null) };
+  // `marks`: the attribute selectors the requesting element (or its form)
+  // matches, for app.js's elt.closest(<selector list>).
+  const fire = ({ status = 200, body, path: reqPath = '/api/v3/anything', reportsItself = false, marks = [] }) => {
+    const elt = {
+      closest: (sel) => (reportsItself || sel.split(',').some(s => marks.includes(s.trim())) ? {} : null),
+    };
     afterRequest({
       target: { closest: () => null },
       detail: {
@@ -100,5 +104,20 @@ console.log('\nhtmx after-request follows the flag, not the URL');
   ok('a flagged answer raises it, even from a form that reports itself', t.banner.style.display === 'block');
 }
 
+console.log('\nthe server message toast');
+{
+  const notes = [];
+  const t = load(notes);
+  const answer = { status: 'success', message: 'Schedule saved' };
+  t.fire({ body: answer });
+  ok('a plain htmx request shows the server message', notes.length === 1 && notes[0][0] === 'Schedule saved', notes);
+  t.fire({ body: answer, marks: ['[hx-on\\:htmx\\:after-request]'] });
+  ok('a form with its own hx-on after-request handler does not', notes.length === 1, notes);
+  // Page modules (js/pages/schedule.js) report a form's save from a listener
+  // and mark the form data-reports-result instead of an hx-on attribute.
+  t.fire({ body: answer, marks: ['[data-reports-result]'] });
+  ok('nor does a form a page module reports for (data-reports-result)', notes.length === 1, notes);
+}
+
 console.log(`\n${pass} passed, ${fail} failed`);
 process.exit(fail ? 1 : 0);

test/test_api_v3_install_restart_installed_id.py

@@ -1,123 +0,0 @@
-"""POST /plugins/install asks for a restart by the id the plugin installed as.
-
-A store install needs a display restart when config.json already enables the
-plugin (a reinstall, or a config carried over): the display loads a plugin
-when its ``enabled`` flag changes, and this flag did not. The route read the
-flag under the registry id it was given. An aliased entry installs under
-another id -- ``weather`` installs a directory whose manifest declares
-``ledmatrix-weather``, and its config section is ``ledmatrix-weather`` -- so
-reinstalling an enabled Weather never reported that a restart was needed,
-and the display kept running the old copy.
-"""
-
-import json
-from unittest.mock import MagicMock
-
-import pytest
-
-from test._api_v3_test_helpers import api_v3_client, api_v3_module  # noqa: F401
-
-INSTALL = "/api/v3/plugins/install"
-
-
-@pytest.fixture
-def store(api_v3_module, tmp_path):
-    """The store installs registry entry ``weather`` as ``installed_id``."""
-    manager = api_v3_module.api_v3.plugin_store_manager
-    manager.install_plugin.return_value = True
-    manager.get_registry_info.return_value = None
-    manager._find_plugin_path.return_value = None
-
-    def installs_as(installed_id):
-        path = tmp_path / installed_id
-        path.mkdir()
-        (path / "manifest.json").write_text(json.dumps({"id": installed_id}),
-                                            encoding="utf-8")
-        manager._find_plugin_path.side_effect = (
-            lambda pid: path if pid == "weather" else None)
-
-    manager.installs_as = installs_as
-    return manager
-
-
-@pytest.fixture
-def config(api_v3_module):
-    """config.json with an ``enabled`` flag for each plugin id given."""
-    def sections(enabled):
-        api_v3_module.api_v3.config_manager.load_config.return_value = {
-            plugin_id: {"enabled": flag} for plugin_id, flag in enabled.items()}
-    return sections
-
-
-@pytest.fixture
-def queued(api_v3_module):
-    queue = MagicMock()
-
-    def enqueue(operation_type, plugin_id, operation_callback=None):
-        queue.callback_result = operation_callback(MagicMock())
-        return "op-1"
-
-    queue.enqueue_operation.side_effect = enqueue
-    api_v3_module.api_v3.operation_queue = queue
-    return queue
-
-
-def _direct(client):
-    return client.post(INSTALL, json={"plugin_id": "weather"}).get_json()
-
-
-def _queued(client, queue):
-    client.post(INSTALL, json={"plugin_id": "weather"})
-    return queue.callback_result
-
-
-class TestDirectInstall:
-    def test_an_aliased_install_enabled_under_its_installed_id_asks_for_a_restart(
-            self, api_v3_client, store, config):
-        store.installs_as("ledmatrix-weather")
-        config({"ledmatrix-weather": True})
-        body = _direct(api_v3_client)
-        assert body["status"] == "success"
-        assert body["restart_required"] is True
-        assert body["restart_message"]
-
-    def test_an_enabled_section_under_the_registry_id_alone_does_not(
-            self, api_v3_client, store, config):
-        """The display knows the plugin as ledmatrix-weather; nothing runs
-        under a section called weather."""
-        store.installs_as("ledmatrix-weather")
-        config({"weather": True})
-        assert _direct(api_v3_client)["restart_required"] is False
-
-    def test_an_aliased_install_that_is_not_enabled_needs_no_restart(
-            self, api_v3_client, store, config):
-        store.installs_as("ledmatrix-weather")
-        config({"ledmatrix-weather": False})
-        assert _direct(api_v3_client)["restart_required"] is False
-
-    def test_an_install_under_its_own_id_is_unchanged(self, api_v3_client, store, config):
-        store.installs_as("weather")
-        config({"weather": True})
-        assert _direct(api_v3_client)["restart_required"] is True
-
-    def test_an_install_that_cannot_be_found_uses_the_requested_id(
-            self, api_v3_client, store, config):
-        config({"weather": True})
-        assert _direct(api_v3_client)["restart_required"] is True
-
-
-class TestQueuedInstall:
-    def test_an_aliased_install_enabled_under_its_installed_id_asks_for_a_restart(
-            self, api_v3_client, store, config, queued):
-        store.installs_as("ledmatrix-weather")
-        config({"ledmatrix-weather": True})
-        result = _queued(api_v3_client, queued)
-        assert result["success"] is True
-        assert result["restart_required"] is True
-        assert result["restart_message"]
-
-    def test_an_enabled_section_under_the_registry_id_alone_does_not(
-            self, api_v3_client, store, config, queued):
-        store.installs_as("ledmatrix-weather")
-        config({"weather": True})
-        assert _queued(api_v3_client, queued)["restart_required"] is False

test/test_api_v3_installed_display_modes.py

@@ -29,7 +29,7 @@ def installed(api_v3_module, api_v3_client, tmp_path):
         api.plugin_catalog.plugins_dir = str(tmp_path)  # no manifest on disk
         api.plugin_catalog.get_all_plugin_info = MagicMock(return_value=[info])
         api.plugin_catalog.get_plugin_display_modes = MagicMock(return_value=declared_modes)
-        api.plugin_store_manager.get_registry_info = MagicMock(return_value=None)
+        api.plugin_store_manager.get_cached_registry_info = MagicMock(return_value=None)
         api.config_manager.load_config = MagicMock(return_value={})
         response = api_v3_client.get('/api/v3/plugins/installed')
         assert response.status_code == 200

test/test_api_v3_installed_plugin_icon.py

@@ -22,7 +22,7 @@ def installed(api_v3_module, api_v3_client, tmp_path):
         info.update(manifest_extra)
         api.plugin_catalog.plugins_dir = str(tmp_path)  # no manifest on disk
         api.plugin_catalog.get_all_plugin_info = MagicMock(return_value=[info])
-        api.plugin_store_manager.get_registry_info = MagicMock(return_value=None)
+        api.plugin_store_manager.get_cached_registry_info = MagicMock(return_value=None)
         api.config_manager.load_config = MagicMock(return_value={})
         response = api_v3_client.get('/api/v3/plugins/installed')
         assert response.status_code == 200

test/test_api_v3_on_demand_socket.py

@@ -1,10 +1,13 @@
 """POST /display/on-demand/start and /stop: control socket first, mailbox fallback.
 
 The routes hand the request to the display over the control socket
-(src/ipc) and get an acknowledgement. On any failure -- no socket (a stopped
-display, or one older than the socket), a timeout, a refusal, a bug in the
-client -- they write the file mailbox exactly as they did before the socket
-existed. These tests pin both paths, that exactly one of them is used, that
+(src/ipc) and get an acknowledgement. When the socket could not carry the
+request -- no socket (a stopped display, or one older than the socket), a
+refused or timed-out connect, a display too old to know the command, a bug
+in the client -- they write the file mailbox exactly as they did before the
+socket existed. When the display had the request and failed it (a full
+queue, bad arguments, no answer in time) the route says so and writes
+nothing. These tests pin each path, that at most one of them is used, that
 the response says which, and that the request id is the same either way (the
 display deduplicates on it).
 
@@ -101,12 +104,15 @@ class TestSocketPath:
 class TestMailboxFallback:
     @pytest.mark.parametrize("reason", [
         "no_socket", "refused", "timeout", "closed", "bad_response", "invalid_request",
-        "busy", "unknown_command", "unsupported_version", "disabled", "unsupported",
+        "busy", "forbidden", "unknown_command", "unsupported_version", "disabled",
+        "unsupported",
     ])
-    def test_any_socket_failure_writes_the_mailbox_as_before(
+    def test_a_request_the_socket_never_carried_writes_the_mailbox(
             self, api_v3_client, service, reason):
+        # sent=False: the display never had it (no socket, a refused or
+        # timed-out connect, turned away at the door).
         with patch(f"{CLIENT}.on_demand_start",
-                   side_effect=control_client.ControlError(reason, "x")):
+                   side_effect=control_client.ControlError(reason, "x", sent=False)):
             resp = api_v3_client.post(START_URL, json={
                 "plugin_id": "weather", "mode": "weather_current",
                 "duration": 60, "pinned": True})
@@ -168,6 +174,60 @@ class TestMailboxFallback:
         assert data["socket_error"] in ("disabled", "unsupported")   # Linux, Windows
 
 
+class TestTheDisplayHadIt:
+    """Once the display has the request, its answer stands: no mailbox copy.
+
+    A busy queue, a refusal or silence after the request was sent mean the
+    display may have applied it, or would refuse the mailbox copy too, so
+    the route reports the failure instead of posting it a second time.
+    """
+
+    @pytest.mark.parametrize("reason,status", [
+        ("busy", 503), ("internal", 503), ("timeout", 503), ("closed", 503),
+        ("bad_response", 503), ("invalid_args", 400),
+    ])
+    def test_start_is_answered_with_the_failure(self, api_v3_client, service, reason, status):
+        with patch(f"{CLIENT}.on_demand_start",
+                   side_effect=control_client.ControlError(reason, "x", sent=True)):
+            resp = api_v3_client.post(START_URL, json={"plugin_id": "weather"})
+        assert resp.status_code == status
+        body = resp.get_json()
+        assert body["status"] == "error"
+        assert body["data"]["transport"] == "socket"
+        assert body["data"]["socket_error"] == reason
+        assert _mailbox_writes(service["cache"]) == []
+        assert not [call for call in service["calls"] if call[0] == "systemctl"]
+
+    def test_stop_is_answered_with_the_failure(self, api_v3_client, service):
+        with patch(f"{CLIENT}.on_demand_stop",
+                   side_effect=control_client.ControlError("busy", "x", sent=True)):
+            resp = api_v3_client.post(STOP_URL, json={})
+        assert resp.status_code == 503
+        assert _mailbox_writes(service["cache"]) == []
+
+    def test_a_stop_with_stop_service_still_stops_the_service(self, api_v3_client, service):
+        with patch(f"{CLIENT}.on_demand_stop",
+                   side_effect=control_client.ControlError("timeout", "x", sent=True)), \
+             patch("web_interface.blueprints.api_v3.display._stop_display_service",
+                   return_value={"active": False}) as stop:
+            resp = api_v3_client.post(STOP_URL, json={"stop_service": True})
+        assert resp.status_code == 200
+        data = resp.get_json()["data"]
+        assert data["transport"] == "socket" and data["socket_error"] == "timeout"
+        stop.assert_called_once()
+        assert _mailbox_writes(service["cache"]) == []
+
+    @pytest.mark.parametrize("reason", ["unknown_command", "unsupported_version"])
+    def test_an_older_display_that_does_not_speak_it_gets_the_mailbox(
+            self, api_v3_client, service, reason):
+        # The upgrade case: new web interface, display still on an old build.
+        with patch(f"{CLIENT}.on_demand_start",
+                   side_effect=control_client.ControlError(reason, "x", sent=True)):
+            data = api_v3_client.post(START_URL, json={"plugin_id": "weather"}).get_json()["data"]
+        assert data["transport"] == "mailbox" and data["socket_error"] == reason
+        assert len(_mailbox_writes(service["cache"])) == 1
+
+
 @pytest.mark.skipif(not c.socket_supported(), reason="AF_UNIX sockets are Linux/macOS only")
 class TestRealSocket:
     @pytest.fixture
@@ -204,3 +264,23 @@ class TestRealSocket:
         data = api_v3_client.post(START_URL, json={"plugin_id": "weather"}).get_json()["data"]
         assert data["transport"] == "mailbox" and data["socket_error"] == "no_socket"
         assert len(_mailbox_writes(service["cache"])) == 1
+
+    def test_a_full_queue_is_reported_not_mailed(self, api_v3_client, service, monkeypatch):
+        import shutil
+        import tempfile
+        from src.ipc.server import ControlServer
+        d = tempfile.mkdtemp(prefix="lmipc-")
+        path = os.path.join(d, "control.sock")
+        server = ControlServer(path, status_provider=dict, queue_size=1)
+        assert server.start()
+        monkeypatch.setenv(c.SOCKET_PATH_ENV, path)
+        try:
+            first = api_v3_client.post(START_URL, json={"plugin_id": "weather"})
+            assert first.get_json()["data"]["transport"] == "socket"
+            second = api_v3_client.post(START_URL, json={"plugin_id": "weather"})
+            assert second.status_code == 503
+            assert second.get_json()["data"]["socket_error"] == "busy"
+            assert _mailbox_writes(service["cache"]) == []
+        finally:
+            server.close()
+            shutil.rmtree(d, ignore_errors=True)

test/test_api_v3_status_accuracy.py

@@ -0,0 +1,326 @@
+"""Four web answers that disagreed with the rig they describe (found on ledpi).
+
+1. POST /config/schedule refused the schedule GET returns on a fresh install
+   (config.template.json: per-day, every day off, schedule disabled) with
+   "At least one day must be enabled", as did /config/dim-schedule. A
+   disabled schedule needs no enabled day.
+2. A brightness-only POST /config/main answered ``restart_required: true``,
+   though the display applies brightness live (brightness.set over the
+   socket, and the config watcher). The flag now says whether anything
+   changed that the running display does not pick up by itself.
+3. /health stayed "healthy" with the display service stopped: only the
+   sub-checks changed. Service inactive, no socket and no live heartbeat
+   is now ``display_loop: stopped`` and "degraded".
+4. /display/current-status kept answering ``is_display_active: true`` from
+   the cache for up to 120 s after the display stopped. With no socket and
+   no live heartbeat it is now unknown.
+"""
+
+import copy
+import json
+import os
+import sys
+import time
+from pathlib import Path
+from unittest.mock import patch
+
+import pytest
+
+sys.path.insert(0, str(Path(__file__).parent.parent))
+
+from test._api_v3_test_helpers import api_v3_client, api_v3_module  # noqa: F401,E402
+
+from src import display_watchdog  # noqa: E402
+from src.ipc import client as control_client  # noqa: E402
+from web_interface import display_state  # noqa: E402
+
+REPO = Path(__file__).resolve().parent.parent
+TEMPLATE = json.loads((REPO / 'config' / 'config.template.json').read_text(encoding='utf-8'))
+
+
+@pytest.fixture
+def store(api_v3_module, monkeypatch):
+    state = {'config': {}, 'saves': 0}
+    api_v3_module.api_v3.config_manager.load_config.side_effect = \
+        lambda *a, **k: copy.deepcopy(state['config'])
+
+    def fake_save(_manager, config, **_kwargs):
+        state['config'] = copy.deepcopy(config)
+        state['saves'] += 1
+        return True, ''
+
+    monkeypatch.setattr(api_v3_module, '_save_config_atomic', fake_save)
+    return state
+
+
+# --- 1. schedules ---------------------------------------------------------------
+
+SCHEDULE_ROUTES = [('/api/v3/config/schedule', 'schedule'),
+                   ('/api/v3/config/dim-schedule', 'dim_schedule')]
+
+
+@pytest.mark.parametrize('route,section', SCHEDULE_ROUTES)
+def test_the_templates_disabled_per_day_schedule_saves_back(api_v3_client, store,
+                                                            route, section):
+    stored = copy.deepcopy(TEMPLATE[section])
+    stored['mode'] = 'per-day'
+    assert stored['enabled'] is False
+    assert not any(day['enabled'] for day in stored['days'].values())
+    store['config'] = {section: copy.deepcopy(stored)}
+
+    read = api_v3_client.get(route).get_json()['data']
+    resp = api_v3_client.post(route, json=read)
+
+    assert resp.status_code == 200, resp.get_json()
+    saved = store['config'][section]
+    assert saved['enabled'] is False and saved['mode'] == 'per-day'
+    # The disabled days keep their times: switching one on finds them.
+    assert saved['days'] == stored['days']
+
+
+@pytest.mark.parametrize('route,section', SCHEDULE_ROUTES)
+def test_an_enabled_per_day_schedule_still_needs_a_day(api_v3_client, store, route, section):
+    body = copy.deepcopy(TEMPLATE[section])
+    body.update(enabled=True, mode='per-day')
+    resp = api_v3_client.post(route, json=body)
+    assert resp.status_code == 400
+    assert 'At least one day must be enabled' in resp.get_json()['message']
+    assert store['saves'] == 0
+
+
+@pytest.mark.parametrize('route', [r for r, _ in SCHEDULE_ROUTES])
+def test_the_pickers_form_post_with_every_day_off_saves(api_v3_client, store, route):
+    """What schedule-picker.js posts: flat hidden inputs, booleans as strings,
+    times for every day."""
+    body = {'enabled': 'false', 'mode': 'per_day', 'start_time': '07:00', 'end_time': '23:00'}
+    for day in ('monday', 'tuesday', 'wednesday', 'thursday', 'friday', 'saturday', 'sunday'):
+        body.update({f'{day}_enabled': 'false', f'{day}_start': '06:30', f'{day}_end': '22:15'})
+    resp = api_v3_client.post(route, json=body)
+    assert resp.status_code == 200, resp.get_json()
+
+
+def test_an_invalid_time_on_a_disabled_day_is_dropped_not_refused(api_v3_client, store):
+    body = {'enabled': False, 'mode': 'per-day',
+            'days': {'monday': {'enabled': False, 'start_time': 'soon', 'end_time': '22:00'}}}
+    resp = api_v3_client.post('/api/v3/config/schedule', json=body)
+    assert resp.status_code == 200, resp.get_json()
+    assert store['config']['schedule']['days']['monday'] == {'enabled': False,
+                                                             'end_time': '22:00'}
+
+
+# --- 2. restart_required on /config/main ------------------------------------------
+
+STORED_MAIN = {
+    'timezone': 'America/Chicago',
+    'display': {
+        'hardware': {'rows': 32, 'cols': 64, 'chain_length': 2, 'brightness': 90,
+                     'disable_hardware_pulsing': False, 'inverse_colors': False,
+                     'show_refresh_rate': False},
+        'runtime': {'gpio_slowdown': 4},
+        'display_durations': {'clock': 15},
+        'use_short_date_format': False,
+    },
+}
+
+
+@pytest.fixture
+def main_store(store):
+    store['config'] = copy.deepcopy(STORED_MAIN)
+    return store
+
+
+def _save_main(client, body):
+    with patch('web_interface.blueprints.api_v3.control_client.brightness_set',
+               side_effect=control_client.ControlError('no_socket', 'x')):
+        resp = client.post('/api/v3/config/main', data=json.dumps(body),
+                           content_type='application/json')
+    assert resp.status_code == 200, resp.get_json()
+    return resp.get_json()
+
+
+def test_a_brightness_only_save_needs_no_restart(api_v3_client, main_store):
+    body = _save_main(api_v3_client, {'brightness': 40})
+    assert main_store['config']['display']['hardware']['brightness'] == 40
+    assert body['restart_required'] is False
+
+
+def test_a_brightness_save_on_a_config_without_a_display_section(api_v3_client, store):
+    """The route creates display.hardware and display.runtime on the way;
+    empty sections are not a change."""
+    store['config'] = {}
+    assert _save_main(api_v3_client, {'brightness': 40})['restart_required'] is False
+
+
+def test_the_display_form_with_only_brightness_changed_needs_no_restart(api_v3_client,
+                                                                       main_store):
+    hw = STORED_MAIN['display']['hardware']
+    body = {'__form_section': 'display', 'rows': 32, 'cols': 64, 'chain_length': 2,
+            'brightness': 55, 'gpio_slowdown': 4}
+    body.update({k: 'on' for k in ('disable_hardware_pulsing', 'inverse_colors',
+                                   'show_refresh_rate') if hw[k]})
+    assert _save_main(api_v3_client, body)['restart_required'] is False
+
+
+def test_a_mode_duration_needs_no_restart(api_v3_client, main_store):
+    body = _save_main(api_v3_client, {'duration__clock': 40})
+    assert main_store['config']['display']['display_durations']['clock'] == 40
+    assert body['restart_required'] is False
+
+
+@pytest.mark.parametrize('change', [{'rows': 64}, {'brightness': 40, 'chain_length': 3},
+                                    {'gpio_slowdown': 2}, {'timezone': 'UTC'}])
+def test_a_setting_the_display_reads_at_startup_still_needs_one(api_v3_client, main_store,
+                                                                change):
+    assert _save_main(api_v3_client, change)['restart_required'] is True
+
+
+def test_restart_needed_compares_leaves():
+    from web_interface.blueprints.api_v3.config import restart_needed
+    before = {'display': {'hardware': {'brightness': 90, 'rows': 32}}}
+    assert not restart_needed(before, copy.deepcopy(before))
+    assert not restart_needed(before, {'display': {'hardware': {'brightness': 10, 'rows': 32},
+                                                   'runtime': {}}})
+    assert restart_needed(before, {'display': {'hardware': {'brightness': 90}}})  # removed
+    assert not restart_needed({}, {'clock': {'enabled': True}}, live_paths=[('clock',)])
+    assert restart_needed({}, {'clockwork': {'enabled': True}}, live_paths=[('clock',)])
+
+
+# --- 3 and 4. a stopped display -----------------------------------------------------
+
+@pytest.fixture
+def no_display(monkeypatch, tmp_path):
+    """A Pi whose display service has stopped: the socket is expected here
+    but does not answer, and systemd took the heartbeat's directory away."""
+    monkeypatch.setattr(display_state, 'socket_supported', lambda: True)
+    monkeypatch.setattr(display_state, 'client_socket_paths', lambda: [str(tmp_path / 'gone')])
+    monkeypatch.setattr(display_state, 'read_state', lambda: None)
+    path = tmp_path / 'display-heartbeat.json'
+    monkeypatch.setattr(display_watchdog, 'HEARTBEAT_PATH', str(path))
+
+    def beat(age, pid=None):
+        path.write_text(json.dumps({'pid': os.getpid() if pid is None else pid,
+                                    'mono': time.monotonic() - age,
+                                    'wall': time.time() - age}))
+    return beat
+
+
+@pytest.fixture
+def service(monkeypatch):
+    status = {'active': False, 'returncode': 3, 'stdout': 'inactive', 'stderr': ''}
+    monkeypatch.setattr('web_interface.blueprints.api_v3.misc._get_display_service_status',
+                        lambda: dict(status))
+    return status
+
+
+@pytest.fixture
+def fresh_preview(tmp_path, monkeypatch):
+    """The preview frame the display left behind, under 60 s old: on its own
+    it kept the hardware check "connected"."""
+    from web_interface import display_preview
+    snapshot = tmp_path / 'preview.png'
+    snapshot.write_bytes(b'png')
+    monkeypatch.setattr(display_preview, 'SNAPSHOT_PATH', str(snapshot))
+
+
+def _health(client):
+    resp = client.get('/api/v3/health')
+    assert resp.status_code == 200, resp.get_json()
+    return resp.get_json()['data']
+
+
+class TestHealth:
+    def test_a_stopped_display_service_is_degraded(self, api_v3_client, no_display, service,
+                                                   fresh_preview):
+        data = _health(api_v3_client)
+        assert data['services']['display_service']['status'] == 'inactive'
+        assert data['checks']['display_loop']['status'] == 'stopped'
+        assert data['status'] == 'degraded'
+
+    def test_a_service_still_starting_is_not(self, api_v3_client, no_display, service,
+                                             fresh_preview):
+        """Active, before its socket and first heartbeat: not stopped."""
+        service.update(active=True, stdout='active', returncode=0)
+        data = _health(api_v3_client)
+        assert data['checks']['display_loop']['status'] == 'not_reported'
+        assert data['status'] == 'healthy'
+
+    def test_a_display_run_by_hand_is_not_stopped(self, api_v3_client, no_display, service,
+                                                  fresh_preview):
+        """The service is off but a display process beats (sudo python3 run.py)."""
+        no_display(age=2)
+        data = _health(api_v3_client)
+        assert data['checks']['display_loop']['status'] == 'running'
+        assert data['status'] == 'healthy'
+
+    @pytest.mark.parametrize('platform', ['no_unix_sockets', 'socket_off'])
+    def test_without_a_socket_to_expect_nothing_changes(self, api_v3_client, no_display,
+                                                        service, fresh_preview, monkeypatch,
+                                                        platform):
+        """Windows and the dev server (no systemd unit), or the socket
+        deliberately off: no heartbeat is no signal, as before."""
+        if platform == 'no_unix_sockets':
+            monkeypatch.setattr(display_state, 'socket_supported', lambda: False)
+        else:
+            monkeypatch.setattr(display_state, 'client_socket_paths', lambda: [])
+        service.update(returncode=-1, stdout='', stderr='systemctl not found')
+        data = _health(api_v3_client)
+        assert data['checks']['display_loop']['status'] == 'not_reported'
+        assert data['status'] == 'healthy'
+
+    def test_the_status_only_answer_says_degraded(self, api_v3_client, no_display, service,
+                                                  fresh_preview, monkeypatch):
+        monkeypatch.setattr('web_interface.blueprints.api_v3.misc.request_is_authenticated',
+                            lambda: False)
+        resp = api_v3_client.get('/api/v3/health')
+        assert resp.get_json()['data'] == {'status': 'degraded'}
+
+
+class TestCurrentStatus:
+    CACHED = {'mode': 'clock', 'plugin_id': 'clock', 'is_display_active': True,
+              'on_demand_active': False, 'last_updated': None}
+
+    @pytest.fixture
+    def cached(self, api_v3_module):
+        entry = dict(self.CACHED, last_updated=time.time() - 30)
+        cache = api_v3_module.api_v3.cache_manager
+        cache.get.side_effect = lambda key, *a, **kw: (
+            dict(entry) if key == 'display_current_state' else None)
+        return entry
+
+    def _status(self, client):
+        resp = client.get('/api/v3/display/current-status')
+        assert resp.status_code == 200
+        return resp.get_json()['data']
+
+    def test_a_stopped_display_is_not_reported_active(self, api_v3_client, no_display, cached):
+        data = self._status(api_v3_client)
+        assert not data.get('is_display_active')
+        assert data['mode'] is None and data['last_updated'] is None
+        assert data['source'] == 'cache'
+
+    def test_a_stale_heartbeat_is_not_active_either(self, api_v3_client, no_display, cached):
+        no_display(age=display_watchdog.HEARTBEAT_STALE_SECONDS + 5)
+        assert self._status(api_v3_client)['mode'] is None
+
+    @pytest.mark.skipif(os.name != 'posix', reason='process_exists answers only on POSIX')
+    def test_a_heartbeat_from_a_dead_process_is_not_active(self, api_v3_client, no_display,
+                                                           cached):
+        no_display(age=1, pid=2 ** 22 + 12345)
+        assert self._status(api_v3_client)['mode'] is None
+
+    def test_a_live_heartbeat_without_a_socket_reads_the_cache(self, api_v3_client,
+                                                               no_display, cached):
+        """An older display with no socket, still running."""
+        no_display(age=2)
+        data = self._status(api_v3_client)
+        assert data['mode'] == 'clock' and data['is_display_active'] is True
+
+    @pytest.mark.parametrize('platform', ['no_unix_sockets', 'socket_off'])
+    def test_without_a_socket_to_expect_the_cache_answers(self, api_v3_client, no_display,
+                                                          cached, monkeypatch, platform):
+        if platform == 'no_unix_sockets':
+            monkeypatch.setattr(display_state, 'socket_supported', lambda: False)
+        else:
+            monkeypatch.setattr(display_state, 'client_socket_paths', lambda: [])
+        data = self._status(api_v3_client)
+        assert data['mode'] == 'clock' and data['is_display_active'] is True

test/test_display_arbiter.py

@@ -9,6 +9,7 @@ that overrides the schedule and ends (#714).
 """
 
 import itertools
+from dataclasses import replace
 import os
 from unittest.mock import MagicMock, patch
 
@@ -19,6 +20,7 @@ os.environ.setdefault("EMULATOR", "true")
 from src import display_arbiter  # noqa: E402
 from src.display_arbiter import (  # noqa: E402
     SCHEDULED_OFF_DWELL,
+    SCREEN_PREEMPTERS,
     WIFI_NOTICE_DWELL,
     Arbiter,
     ArbiterInputs,
@@ -26,6 +28,9 @@ from src.display_arbiter import (  # noqa: E402
     ScreenPlan,
     Source,
     WifiNotice,
+    live_pick,
+    live_takeover,
+    on_demand_bound,
     wifi_notice_preempts,
 )
 
@@ -34,7 +39,9 @@ NOTICE = WifiNotice(message="Connected to HomeNet", expires_at=1_000.0)
 OFF = Source.SCHEDULED_OFF
 FOLLOW = Source.FOLLOWER
 WIFI = Source.WIFI
+ONDEM = Source.ON_DEMAND
 LEGACY = Source.LEGACY
+ROTATION = Source.ROTATION
 
 # (schedule_on, on_demand_active, follower_active, notice) -> Source.
 # Every combination of the stage-2 inputs: 2 x 2 x 2 x 2 = 16 rows.
@@ -46,17 +53,17 @@ DECIDE_TABLE = [
     (False, False, True, None, OFF),
     (False, False, True, NOTICE, OFF),
     # Scheduled off, but on-demand overrides the gate.
-    (False, True, False, None, LEGACY),       # on-demand: run() decides
-    (False, True, False, NOTICE, LEGACY),     # on-demand outranks WiFi
+    (False, True, False, None, ONDEM),        # on-demand overrides the gate
+    (False, True, False, NOTICE, ONDEM),      # on-demand outranks WiFi
     (False, True, True, None, FOLLOW),        # follower outranks on-demand
     (False, True, True, NOTICE, FOLLOW),
     # Scheduled on.
-    (True, False, False, None, LEGACY),       # live / Vegas / rotation
+    (True, False, False, None, ROTATION),     # live / Vegas / rotation
     (True, False, False, NOTICE, WIFI),
     (True, False, True, None, FOLLOW),
     (True, False, True, NOTICE, FOLLOW),      # follower outranks WiFi
-    (True, True, False, None, LEGACY),
-    (True, True, False, NOTICE, LEGACY),      # on-demand outranks WiFi
+    (True, True, False, None, ONDEM),
+    (True, True, False, NOTICE, ONDEM),       # on-demand outranks WiFi
     (True, True, True, None, FOLLOW),
     (True, True, True, NOTICE, FOLLOW),
 ]
@@ -95,8 +102,15 @@ class TestDecide:
         elif expected is WIFI:
             assert plan == ScreenPlan(WIFI, max_duration=WIFI_NOTICE_DWELL,
                                       notice=NOTICE)
+        elif expected is ONDEM:
+            # An empty state: a session with no modes, which the
+            # controller ends (see TestOnDemand for real sessions).
+            assert plan == ScreenPlan(ONDEM)
+        elif expected is ROTATION:
+            # No live scan and Vegas off: the rotation's (empty) mode.
+            assert plan == ScreenPlan(ROTATION, preemptible_by=SCREEN_PREEMPTERS)
         else:
-            # A follower paces itself; LEGACY is run()'s existing code.
+            # A follower paces itself.
             assert plan == ScreenPlan(expected)
 
     def test_dwells_are_todays(self):
@@ -224,16 +238,389 @@ class TestControllerSnapshot:
             assert (plan.source is OFF) is (not dc.is_display_active), time_str
             return plan.source
 
-        assert step("22:59:30") is LEGACY
+        assert step("22:59:30") is ROTATION
         assert step("23:00:00") is OFF                 # window ends
         dc.on_demand_active = True
-        assert step("23:00:10") is LEGACY              # on-demand overrides
+        assert step("23:00:10") is ONDEM               # on-demand overrides
         assert dc.on_demand_schedule_override is True
-        assert step("23:01:00") is LEGACY              # next minute, still on
+        assert step("23:01:00") is ONDEM               # next minute, still on
         dc._reset_on_demand_fields()                   # session ends
         assert step("23:01:20") is OFF                 # same minute: blanks
         dc.on_demand_active = True
-        assert step("06:59:00") is LEGACY
-        assert step("07:00:00") is LEGACY              # schedule back on mid-session
+        assert step("06:59:00") is ONDEM
+        assert step("07:00:00") is ONDEM               # schedule back on mid-session
         dc._reset_on_demand_fields()
-        assert step("07:00:30") is LEGACY
+        assert step("07:00:30") is ROTATION
+
+
+# -- OnDemand (stage 3) ---------------------------------------------------
+
+ON = ArbiterInputs(schedule_on=True, on_demand_active=True, follower_active=False)
+
+
+def _session(modes=("a", "b", "c"), index=0, expires_at=None, current=None):
+    return ArbiterState(current_mode=current, on_demand_modes=tuple(modes),
+                        on_demand_index=index, on_demand_expires_at=expires_at)
+
+
+class TestOnDemand:
+
+    # (modes, index, expires_at, now) -> (mode, max_duration)
+    TABLE = [
+        (("a", "b", "c"), 0, None, 100.0, "a", None),       # untimed
+        (("a", "b", "c"), 2, None, 100.0, "c", None),
+        (("a", "b", "c"), 3, None, 100.0, "a", None),       # past the end: 0
+        (("a", "b", "c"), 9, None, 100.0, "a", None),
+        (("a",), 0, 130.0, 100.0, "a", 30.0),               # 30 s left
+        (("a",), 0, 130.0, 130.0, "a", 0.0),                # none left
+        (("a",), 0, 130.0, 200.0, "a", 0.0),                # never negative
+    ]
+
+    @pytest.mark.parametrize("modes,index,expires_at,now,mode,max_duration", TABLE)
+    def test_current_mode_and_time_left(self, modes, index, expires_at, now, mode,
+                                        max_duration):
+        plan = Arbiter.decide(_session(modes, index, expires_at), ON, now)
+        assert plan.source is ONDEM
+        assert plan.mode == mode
+        assert plan.max_duration == max_duration
+        assert plan.deadline == expires_at
+
+    def test_no_modes_left_is_a_plan_with_no_mode(self):
+        plan = Arbiter.decide(_session(modes=()), ON, 0.0)
+        assert plan == ScreenPlan(ONDEM)
+
+    def test_preemptible_by_the_schedule_a_reload_and_its_own_changes(self):
+        plan = Arbiter.decide(_session(), ON, 0.0)
+        assert {Source.SCHEDULED_OFF, ONDEM, Source.RELOAD} <= plan.preemptible_by
+        assert Source.FOLLOWER not in plan.preemptible_by
+
+    @pytest.mark.parametrize("index,expected_index,expected_mode", [
+        (0, 1, "b"), (1, 2, "c"), (2, 0, "a")])
+    def test_next_on_demand_wraps(self, index, expected_index, expected_mode):
+        nxt = _session(index=index).next_on_demand()
+        assert (nxt.on_demand_index, nxt.current_mode) == (expected_index, expected_mode)
+
+    def test_showing_a_plan_resets_an_index_past_the_end(self):
+        state = _session(index=5, current="x")
+        plan = Arbiter.decide(state, ON, 0.0)
+        shown = state.showing(plan)
+        assert (shown.on_demand_index, shown.current_mode) == (0, "a")
+        assert state.on_demand_index == 5            # not mutated
+
+
+# (min, max, deadline, now) -> bounds. The bound applied after the first frame.
+BOUND_TABLE = [
+    (10.0, 20.0, None, 0.0, (10.0, 20.0)),      # untimed: unchanged
+    (10.0, 20.0, 100.0, 50.0, (10.0, 20.0)),    # plenty left
+    (10.0, 20.0, 100.0, 85.0, (10.0, 15.0)),    # max cut to what is left
+    (10.0, 20.0, 100.0, 95.0, (5.0, 5.0)),      # both cut
+    (10.0, 20.0, 100.0, 100.0, None),           # nothing left
+    (10.0, 20.0, 100.0, 150.0, None),
+]
+
+
+@pytest.mark.parametrize("min_d,max_d,deadline,now,expected", BOUND_TABLE)
+def test_on_demand_bound(min_d, max_d, deadline, now, expected):
+    assert on_demand_bound(min_d, max_d, deadline, now) == expected
+
+
+# -- Live (stage 3) -------------------------------------------------------
+
+LIVE = Source.LIVE
+
+# (live_modes, current_mode, advance) -> pick. _check_live_priority's rule.
+PICK_TABLE = [
+    ((), "clock", True, None),
+    (None, "clock", True, None),
+    (("nfl",), "clock", True, "nfl"),                 # not on a live mode: first
+    (("nfl", "nhl"), "clock", True, "nfl"),
+    (("nfl", "nhl"), "clock", False, "nfl"),
+    (("nfl", "nhl"), "nfl", True, "nhl"),             # round-robin
+    (("nfl", "nhl"), "nhl", True, "nfl"),             # wraps
+    (("nfl", "nhl"), "nhl", False, "nhl"),            # a peek stays put
+    (("nfl",), "nfl", True, "nfl"),                   # one game: itself
+]
+
+
+@pytest.mark.parametrize("live,current,advance,expected", PICK_TABLE)
+def test_live_pick(live, current, advance, expected):
+    assert live_pick(live, current, advance) == expected
+
+
+def _below(live=None, vegas=False, keeps=False, yielded=False, on_demand=False):
+    """Inputs for the Sources below the notice (no notice, no follower)."""
+    return ArbiterInputs(schedule_on=True, on_demand_active=on_demand,
+                         follower_active=False, live_modes=live, vegas_enabled=vegas,
+                         vegas_live_in_ticker=keeps, vegas_yielded=yielded)
+
+
+ROT = ("clock", "weather", "nfl_live", "nhl_live")
+
+
+def _rot(current="clock", index=0, resume=None, unshown=False):
+    return ArbiterState(current_mode=current, rotation=ROT, rotation_index=index,
+                        live_resume_index=resume, live_takeover_unshown=unshown)
+
+
+class TestLive:
+
+    # (state, inputs) -> (source, mode, ends_live)
+    TABLE = [
+        # Nothing live, nothing to resume.
+        (_rot(), _below(live=()), "below", None, False),
+        # Not scanned (on-demand, or the ticker keeps live content).
+        (_rot(), _below(live=None), "below", None, False),
+        # A game is live: it takes the panel.
+        (_rot(), _below(live=("nfl_live",)), LIVE, "nfl_live", False),
+        # Two: round-robin from the one showing.
+        (_rot("nfl_live", 2), _below(live=("nfl_live", "nhl_live")), LIVE, "nhl_live", False),
+        # ... unless a mid-screen takeover chose it and it has not shown yet.
+        (_rot("nfl_live", 2, resume=0, unshown=True),
+         _below(live=("nfl_live", "nhl_live")), LIVE, "nfl_live", False),
+        # Vegas keeps live content in its ticker: Live has no say at all,
+        # not even the resume.
+        (_rot(), _below(live=("nfl_live",), vegas=True, keeps=True), "below", None, False),
+        (_rot("nfl_live", 2, resume=1),
+         _below(live=(), vegas=True, keeps=True), "below", None, False),
+        # Vegas that yields to live content: Live outranks it.
+        (_rot(), _below(live=("nfl_live",), vegas=True), LIVE, "nfl_live", False),
+        # The game ended: the interrupted rotation resumes.
+        (_rot("nfl_live", 2, resume=1), _below(live=()), "below", None, True),
+        (_rot("nfl_live", 2, resume=1), _below(live=(), vegas=True), "below", None, True),
+        # On-demand outranks Live.
+        (ArbiterState(on_demand_modes=("x",)), _below(live=("nfl_live",), on_demand=True),
+         ONDEM, "x", False),
+    ]
+
+    @pytest.mark.parametrize("state,inputs,source,mode,ends_live", TABLE)
+    def test_decide(self, state, inputs, source, mode, ends_live):
+        plan = Arbiter.decide(state, inputs, 0.0)
+        if source == "below":
+            assert plan.source not in (LIVE, ONDEM, OFF, FOLLOW, WIFI)
+        else:
+            assert plan.source is source
+            assert plan.mode == mode
+        assert plan.ends_live is ends_live
+
+    def test_a_live_plan_has_no_durations_until_its_first_frame(self):
+        plan = Arbiter.decide(_rot(), _below(live=("nfl_live",)), 0.0)
+        assert (plan.min_duration, plan.max_duration, plan.frame_policy) == (None, None, None)
+
+
+class TestLiveTransitions:
+
+    def test_claim_saves_where_the_rotation_was(self):
+        nxt = _rot("weather", 1).claim_live("nfl_live")
+        assert (nxt.current_mode, nxt.rotation_index, nxt.live_resume_index) == ("nfl_live", 2, 1)
+
+    def test_a_second_claim_keeps_the_first_resume_point(self):
+        nxt = _rot("nfl_live", 2, resume=1).claim_live("nhl_live")
+        assert (nxt.current_mode, nxt.rotation_index, nxt.live_resume_index) == ("nhl_live", 3, 1)
+
+    def test_claiming_the_mode_showing_changes_nothing(self):
+        state = _rot("nfl_live", 2, resume=1)
+        assert state.claim_live("nfl_live") is state
+
+    def test_a_live_mode_outside_the_rotation_keeps_the_index(self):
+        nxt = _rot("weather", 1).claim_live("mlb_live")
+        assert (nxt.current_mode, nxt.rotation_index, nxt.live_resume_index) == ("mlb_live", 1, 1)
+
+    def test_release_resumes_and_forgets(self):
+        nxt = _rot("nhl_live", 3, resume=1).release_live()
+        assert (nxt.current_mode, nxt.rotation_index, nxt.live_resume_index) == ("weather", 1, None)
+
+    def test_release_wraps_a_resume_point_past_a_shortened_rotation(self):
+        nxt = _rot("nhl_live", 3, resume=6).release_live()
+        assert (nxt.current_mode, nxt.rotation_index) == ("nfl_live", 2)   # 6 % 4
+
+    def test_release_with_nothing_to_resume_changes_nothing(self):
+        state = _rot("clock", 0)
+        assert state.release_live() is state
+        empty = ArbiterState(current_mode="x", live_resume_index=2)
+        assert empty.release_live() is empty      # no rotation to resume into
+
+
+# -- Vegas and Rotation (stage 3) -----------------------------------------
+
+class TestVegasAndRotation:
+
+    # (state, inputs) -> (source, mode, ends_live). LEGACY now means Vegas only.
+    TABLE = [
+        (_rot("weather", 1), _below(live=()), ROTATION, "weather", False),
+        (_rot("weather", 1), _below(live=None), ROTATION, "weather", False),
+        (_rot("weather", 1), _below(live=(), vegas=True), LEGACY, None, False),
+        (_rot("weather", 1), _below(live=None, vegas=True, keeps=True), LEGACY, None, False),
+        # The iteration yielded: the screen it fell through to.
+        (_rot("weather", 1), _below(live=(), vegas=True, yielded=True),
+         ROTATION, "weather", False),
+        (_rot("weather", 1), _below(live=("nfl_live",), vegas=True, yielded=True),
+         LIVE, "nfl_live", False),
+        # Live priority just ended: the rotation resumes where it was cut.
+        (_rot("nhl_live", 3, resume=1), _below(live=()), ROTATION, "weather", True),
+        # ... and Vegas carries the resume through to its own pass.
+        (_rot("nhl_live", 3, resume=1), _below(live=(), vegas=True), LEGACY, None, True),
+        # A rotation that something moved off its list carries on from there.
+        (ArbiterState(current_mode=None, rotation=ROT), _below(live=()), ROTATION, None, False),
+    ]
+
+    @pytest.mark.parametrize("state,inputs,source,mode,ends_live", TABLE)
+    def test_decide(self, state, inputs, source, mode, ends_live):
+        plan = Arbiter.decide(state, inputs, 0.0)
+        assert (plan.source, plan.mode, plan.ends_live) == (source, mode, ends_live)
+
+    def test_a_rotation_plan_may_be_preempted_by_everything_a_screen_watches(self):
+        plan = Arbiter.decide(_rot(), _below(live=()), 0.0)
+        assert plan.preemptible_by == SCREEN_PREEMPTERS
+        assert {OFF, ONDEM, WIFI, LIVE, ROTATION, Source.RELOAD} == SCREEN_PREEMPTERS
+
+
+class _End:
+    def __init__(self, on_demand_active=False, still_live=False):
+        self.on_demand_active = on_demand_active
+        self.still_live = still_live
+
+
+class TestAfter:
+    """ArbiterState.after: _advance_after_screen's step."""
+
+    def test_the_rotation_advances(self):
+        nxt = _rot("weather", 1).after(_End())
+        assert (nxt.current_mode, nxt.rotation_index) == ("nfl_live", 2)
+
+    def test_it_wraps(self):
+        nxt = _rot("nhl_live", 3).after(_End())
+        assert (nxt.current_mode, nxt.rotation_index) == ("clock", 0)
+
+    def test_a_live_mode_still_live_holds(self):
+        state = _rot("nfl_live", 2)
+        assert state.after(_End(still_live=True)) is state
+
+    def test_an_on_demand_session_moves_to_its_next_mode(self):
+        state = replace(_session(index=1, current="b"), rotation=ROT, rotation_index=1)
+        nxt = state.after(_End(on_demand_active=True))
+        assert (nxt.current_mode, nxt.on_demand_index, nxt.rotation_index) == ("c", 2, 1)
+
+    def test_a_session_with_no_modes_is_left_to_the_controller(self):
+        state = ArbiterState(current_mode="x", rotation=ROT)
+        assert state.after(_End(on_demand_active=True)) is state
+
+    def test_no_rotation_no_step(self):
+        state = ArbiterState(current_mode="x")
+        assert state.after(_End()) is state
+
+
+# -- Mid-screen: decide(..., running=plan) (stage 3) ----------------------
+#
+# What the ScreenRunner asks at each service point. These rows are what
+# _check_live_takeover, _screen_preempted and _wifi_notice_pending answered
+# between frames before stage 3, written out.
+
+CLOCK = Arbiter.decide(ArbiterState(current_mode="clock"), _below(live=()), 0.0)
+NFL = Arbiter.decide(ArbiterState(current_mode="clock"), _below(live=("nfl_live",)), 0.0)
+OD = Arbiter.decide(_session(modes=("x", "y")), ON, 0.0)
+FRESH = WifiNotice(message="AP mode", expires_at=1_000.0)
+
+HELD = "held"
+
+
+def _mid(on_demand=False, schedule_on=True, live=None, notice=None, reload=False):
+    return ArbiterInputs(schedule_on=schedule_on, on_demand_active=on_demand,
+                         follower_active=False, live_modes=live, wifi_notice=notice,
+                         reload_pending=reload)
+
+
+# (running, current_mode, inputs, now) -> HELD or (source, mode)
+MID_TABLE = [
+    # Nothing changed.
+    (CLOCK, "clock", _mid(), 500.0, HELD),
+    (CLOCK, "clock", _mid(live=()), 500.0, HELD),
+    # A game went live: it takes the panel (the first live mode).
+    (CLOCK, "clock", _mid(live=("nfl_live", "nhl_live")), 500.0, (LIVE, "nfl_live")),
+    # ... even with a notice pending: the claim is made now, and the next
+    # pass shows the notice first (top-of-pass order), then the game.
+    (CLOCK, "clock", _mid(live=("nfl_live",), notice=FRESH), 500.0, (LIVE, "nfl_live")),
+    # ... but not over the schedule or an on-demand session.
+    (CLOCK, "clock", _mid(live=("nfl_live",), schedule_on=False), 500.0, (OFF, None)),
+    (CLOCK, "x", _mid(live=("nfl_live",), on_demand=True), 500.0, (ONDEM, "x")),
+    # A screen already on a live mode is not taken over by another.
+    (CLOCK, "nfl_live", _mid(live=("nfl_live", "nhl_live")), 500.0, (ROTATION, "nfl_live")),
+    (NFL, "nfl_live", _mid(live=("nhl_live",)), 500.0, HELD),
+    # The mode moved under the screen: on-demand started, or ended, or the
+    # rotation was rebuilt.
+    (CLOCK, "x", _mid(on_demand=True), 500.0, (ONDEM, "x")),
+    (OD, "weather", _mid(), 500.0, (ROTATION, "weather")),
+    (CLOCK, "weather", _mid(), 500.0, (ROTATION, "weather")),
+    # An on-demand session that ends on the same mode keeps the screen.
+    (OD, "x", _mid(), 500.0, HELD),
+    # The schedule: off ends it; an on-demand override holds.
+    (CLOCK, "clock", _mid(schedule_on=False), 500.0, (OFF, None)),
+    (OD, "x", _mid(on_demand=True, schedule_on=False), 500.0, HELD),
+    # A WiFi notice, compared with its expiry; on-demand outranks it.
+    (CLOCK, "clock", _mid(notice=FRESH), 999.9, (WIFI, None)),
+    (CLOCK, "clock", _mid(notice=FRESH), 1_000.0, HELD),
+    (NFL, "nfl_live", _mid(notice=FRESH), 500.0, (WIFI, None)),
+    (OD, "x", _mid(on_demand=True, notice=FRESH), 500.0, HELD),
+    # A plugin reload waits at the top of the loop.
+    (CLOCK, "clock", _mid(reload=True), 500.0, (Source.RELOAD, None)),
+    (OD, "x", _mid(on_demand=True, reload=True), 500.0, (Source.RELOAD, None)),
+    # The order between them: a moved mode before the schedule, the
+    # schedule before a notice, a notice before a reload.
+    (CLOCK, "weather", _mid(schedule_on=False), 500.0, (ROTATION, "weather")),
+    (CLOCK, "clock", _mid(schedule_on=False, notice=FRESH), 500.0, (OFF, None)),
+    (CLOCK, "clock", _mid(notice=FRESH, reload=True), 500.0, (WIFI, None)),
+]
+
+
+class TestMidScreen:
+
+    @pytest.mark.parametrize("running,current,inputs,now,expected", MID_TABLE)
+    def test_decide(self, running, current, inputs, now, expected):
+        state = ArbiterState(current_mode=current)
+        plan = Arbiter.decide(state, inputs, now, running=running)
+        if expected == HELD:
+            assert plan is running
+        else:
+            assert plan is not running
+            assert (plan.source, plan.mode) == expected
+
+    def test_the_running_plans(self):
+        assert (CLOCK.source, CLOCK.mode) == (ROTATION, "clock")
+        assert (NFL.source, NFL.mode) == (LIVE, "nfl_live")
+        assert LIVE not in NFL.preemptible_by
+        assert (OD.source, OD.mode) == (ONDEM, "x")
+
+    def test_a_follower_and_vegas_never_preempt(self):
+        for plan in (CLOCK, NFL, OD):
+            assert FOLLOW not in plan.preemptible_by
+            assert LEGACY not in plan.preemptible_by
+
+    def test_nothing_in_preemptible_by_means_nothing_preempts(self):
+        bare = replace(CLOCK, preemptible_by=frozenset())
+        inputs = _mid(live=("nfl_live",), schedule_on=False, notice=FRESH, reload=True)
+        assert Arbiter.decide(ArbiterState(current_mode="weather"), inputs, 0.0,
+                              running=bare) is bare
+
+    def test_mid_screen_decide_reads_no_clock(self):
+        boom = MagicMock(side_effect=AssertionError("decide read the clock"))
+        with patch("time.time", boom), patch("time.monotonic", boom):
+            for running, current, inputs, now, _ in MID_TABLE:
+                Arbiter.decide(ArbiterState(current_mode=current), inputs, now,
+                               running=running)
+
+
+# (current, inputs) -> live_takeover. The mode a mid-screen check claims.
+TAKEOVER_TABLE = [
+    ("clock", _mid(live=("nfl_live",)), "nfl_live"),
+    ("clock", _mid(live=()), None),
+    ("clock", _mid(live=None), None),                       # no scan was due
+    ("nfl_live", _mid(live=("nfl_live",)), None),
+    ("clock", _mid(live=("nfl_live",), on_demand=True), None),
+    ("clock", _mid(live=("nfl_live",), schedule_on=False), None),
+    ("clock", replace(_mid(live=("nfl_live",)), vegas_enabled=True,
+                      vegas_live_in_ticker=True), None),
+]
+
+
+@pytest.mark.parametrize("current,inputs,expected", TAKEOVER_TABLE)
+def test_live_takeover(current, inputs, expected):
+    assert live_takeover(ArbiterState(current_mode=current), inputs) == expected

test/test_display_hold_report.py

@@ -0,0 +1,142 @@
+"""The report of a scrolling screen held by its plugin's update().
+
+While a plugin's update() runs it holds the plugin's lock, and its screen's
+frames are skipped -- on a scroller, a frozen strip -- with nothing logged.
+_note_display_hold times each such run and reports one of
+DISPLAY_HOLD_REPORT_SECONDS or more.
+"""
+
+import threading
+import types
+from unittest.mock import MagicMock
+
+import pytest
+
+
+class _Clock:
+    """display_controller's clock: moves only when run() sleeps or a test says."""
+
+    def __init__(self, start=10_000.0):
+        self.t = start
+
+    def now(self):
+        return self.t
+
+    def sleep(self, seconds):
+        self.t += max(seconds, 0.0005)
+
+    def module(self):
+        return types.SimpleNamespace(time=self.now, monotonic=self.now,
+                                     perf_counter=self.now, sleep=self.sleep)
+
+
+@pytest.fixture
+def clock(monkeypatch):
+    c = _Clock()
+    monkeypatch.setattr("src.display_controller.time", c.module())
+    return c
+
+
+class _Locks:
+    """get_plugin_lock for one plugin, whose lock the test can hold."""
+
+    def __init__(self):
+        self.lock = threading.Lock()
+
+    def __call__(self, plugin_id):
+        return self.lock
+
+
+@pytest.fixture
+def held(test_display_controller):
+    c = test_display_controller
+    locks = _Locks()
+    c.plugin_manager.get_plugin_lock = locks
+    c.plugin_manager._warn_rate_limited = MagicMock()
+    c.plugin_manager.health_tracker = MagicMock()
+    c._display_hold = None
+    return c, locks.lock
+
+
+def _plugin(plugin_id):
+    p = MagicMock()
+    p.plugin_id = plugin_id
+    p.display.return_value = True
+    return p
+
+
+class TestTheDisplayHoldReport:
+    def test_a_long_hold_is_reported_when_it_ends(self, held, clock):
+        c, lock = held
+        ticker = _plugin("ticker")
+        lock.acquire()                         # update() running
+        assert c._display_once(ticker, "ticker", False, report_hold=True) is True
+        clock.t += 0.2
+        assert c._display_once(ticker, "ticker", False, report_hold=True) is True
+        assert ticker.display.call_count == 0
+        c.plugin_manager._warn_rate_limited.assert_not_called()
+        clock.t += 0.2
+        lock.release()                         # update() done
+        c._display_once(ticker, "ticker", False, report_hold=True)
+        assert ticker.display.call_count == 1
+        key, message, plugin_id, ms = c.plugin_manager._warn_rate_limited.call_args[0]
+        assert key == "display-hold:ticker" and plugin_id == "ticker"
+        assert "held" in message and ms == pytest.approx(400.0)
+        c.plugin_manager.health_tracker.record_busy_skip.assert_called_once_with(
+            "ticker", "display hold", pytest.approx(0.4))
+
+    def test_a_short_hold_is_not(self, held, clock):
+        c, lock = held
+        ticker = _plugin("ticker")
+        lock.acquire()
+        c._display_once(ticker, "ticker", False, report_hold=True)
+        clock.t += 0.1
+        lock.release()
+        c._display_once(ticker, "ticker", False, report_hold=True)
+        c.plugin_manager._warn_rate_limited.assert_not_called()
+        c.plugin_manager.health_tracker.record_busy_skip.assert_not_called()
+
+    def test_a_hold_that_ends_on_another_plugins_screen_is_not_blamed_on_it(
+            self, held, clock):
+        c, lock = held
+        lock.acquire()
+        c._display_once(_plugin("ticker"), "ticker", False, report_hold=True)
+        clock.t += 1.0
+        lock.release()
+        c._display_once(_plugin("clock"), "clock", False, report_hold=True)
+        c.plugin_manager._warn_rate_limited.assert_not_called()
+        assert c._display_hold is None
+
+    def test_frames_that_draw_report_nothing(self, held, clock):
+        c, _lock = held
+        ticker = _plugin("ticker")
+        for _ in range(5):
+            c._display_once(ticker, "ticker", False, report_hold=True)
+            clock.t += 0.5
+        c.plugin_manager._warn_rate_limited.assert_not_called()
+
+    def test_the_1hz_loop_reports_no_holds(self, held, clock):
+        # A static screen's frames are a second apart: one skipped frame is
+        # not a measured hold, and nothing on the panel froze. (On ledpi the
+        # first version reported every such skip as "held 1000 ms".)
+        c, lock = held
+        board = _plugin("board")
+        lock.acquire()
+        c._display_once(board, "board", False)
+        clock.t += 1.0
+        lock.release()
+        c._display_once(board, "board", False)
+        c.plugin_manager._warn_rate_limited.assert_not_called()
+        c.plugin_manager.health_tracker.record_busy_skip.assert_not_called()
+
+    def test_a_run_left_open_is_dropped_by_a_1hz_frame(self, held, clock):
+        c, lock = held
+        ticker = _plugin("ticker")
+        lock.acquire()
+        c._display_once(ticker, "ticker", False, report_hold=True)
+        lock.release()
+        c._display_once(ticker, "ticker", False)        # the 1 Hz loop draws
+        assert c._display_hold is None
+        clock.t += 5.0
+        c._display_once(ticker, "ticker", False, report_hold=True)
+        c.plugin_manager._warn_rate_limited.assert_not_called()

test/test_error_snapshot_cross_process.py

@@ -430,6 +430,157 @@ class TestClear:
         assert "clear request" in response.get_json()["message"]
 
 
+CLIENT = "web_interface.blueprints.api_v3.control_client"
+
+
+def _mailbox_file(shared_cache):
+    _, _, directory = shared_cache
+    return directory / f"{ERROR_CLEAR_REQUEST_KEY}.json"
+
+
+class TestClearOverTheSocket:
+    """``errors.clear``: the display applies the clear before it answers, and
+    the mailbox is written only when the socket could not carry it."""
+
+    @pytest.fixture
+    def socket_up(self, display, monkeypatch):
+        """The control socket, as the display serves it: errors_clear runs
+        the display's own handler against its publisher."""
+        from src.ipc import client as control_client
+        from src.ipc.contract import ErrorsClearArgs
+        _, publisher, _ = display
+        monkeypatch.setattr(errors, "_snapshot_publisher", publisher)
+        calls = []
+
+        def errors_clear(request_id, cutoff, **kw):
+            calls.append((request_id, cutoff))
+            return errors.apply_error_clear(request_id, ErrorsClearArgs(cutoff=cutoff))
+
+        monkeypatch.setattr(f"{CLIENT}.errors_clear", errors_clear)
+        assert control_client.errors_clear is errors_clear
+        return calls
+
+    def test_socket_clear_is_applied_before_the_answer(self, web, display, socket_up,
+                                                       shared_cache):
+        aggregator, publisher, _ = display
+        for _ in range(3):
+            _fail(aggregator)
+        publisher.tick()
+        response = web.post("/api/v3/errors/clear", json={"all": True})
+        assert response.status_code == 200
+        body = response.get_json()
+        data = body["data"]
+        assert data["transport"] == "socket" and data["applied"] is True
+        assert data["cleared_count"] == 3
+        assert body["message"] == "Cleared all errors"
+        [(request_id, _)] = socket_up
+        assert data["request_id"] == request_id
+        # Applied already: no display tick needed, nothing pending.
+        assert aggregator.get_error_summary()["total_errors"] == 0
+        summary = _summary(web)
+        assert summary["total_errors"] == 0 and summary["clear_pending"] is False
+        # And no mailbox file.
+        assert not _mailbox_file(shared_cache).exists()
+
+    def test_an_older_mailbox_request_does_not_read_as_pending(self, web, display, socket_up,
+                                                               shared_cache, monkeypatch):
+        # A clear that went to the mailbox while the socket was down, then a
+        # wider one over the socket: the old request has nothing left to hide.
+        from unittest.mock import patch
+        from src.ipc import client as control_client
+        aggregator, publisher, _ = display
+        _fail(aggregator)
+        publisher.tick()
+        with patch(f"{CLIENT}.errors_clear",
+                   side_effect=control_client.ControlError("no_socket")):
+            data = web.post("/api/v3/errors/clear", json={"max_age_hours": 1}).get_json()["data"]
+        assert data["transport"] == "mailbox"
+        assert _mailbox_file(shared_cache).exists()
+        data = web.post("/api/v3/errors/clear", json={"all": True}).get_json()["data"]
+        assert data["transport"] == "socket"
+        assert _summary(web)["clear_pending"] is False
+
+    @pytest.mark.parametrize("reason", ["no_socket", "refused", "disabled", "unsupported"])
+    def test_no_socket_writes_the_mailbox(self, web, display, shared_cache, monkeypatch, reason):
+        from src.ipc import client as control_client
+        monkeypatch.setattr(f"{CLIENT}.errors_clear", MagicMock(
+            side_effect=control_client.ControlError(reason, sent=False)))
+        aggregator, publisher, _ = display
+        _fail(aggregator)
+        publisher.tick()
+        data = web.post("/api/v3/errors/clear", json={"all": True}).get_json()["data"]
+        assert data["transport"] == "mailbox" and data["applied"] is False
+        assert _mailbox_file(shared_cache).exists()
+        assert _summary(web)["clear_pending"] is True
+        publisher.tick()
+        assert aggregator.get_error_summary()["total_errors"] == 0
+
+    def test_an_older_display_gets_the_mailbox(self, web, display, shared_cache, monkeypatch):
+        # The upgrade case: new web interface, a display from before errors.clear.
+        from src.ipc import client as control_client
+        monkeypatch.setattr(f"{CLIENT}.errors_clear", MagicMock(
+            side_effect=control_client.ControlError("unknown_command", sent=True)))
+        aggregator, publisher, _ = display
+        _fail(aggregator)
+        publisher.tick()
+        data = web.post("/api/v3/errors/clear", json={"all": True}).get_json()["data"]
+        assert data["transport"] == "mailbox"
+        publisher.tick()
+        assert aggregator.get_error_summary()["total_errors"] == 0
+
+    @pytest.mark.parametrize("reason", ["internal", "timeout", "busy", "invalid_args"])
+    def test_a_display_that_had_it_and_failed_is_an_error(self, web, display, shared_cache,
+                                                         monkeypatch, reason):
+        from src.ipc import client as control_client
+        monkeypatch.setattr(f"{CLIENT}.errors_clear", MagicMock(
+            side_effect=control_client.ControlError(reason, sent=True)))
+        response = web.post("/api/v3/errors/clear", json={"all": True})
+        assert response.status_code == 503
+        assert response.get_json()["context"]["socket_error"] == reason
+        assert not _mailbox_file(shared_cache).exists()
+
+
+class TestPublisherMailboxPoll:
+    def test_the_mailbox_is_read_only_when_its_file_changed(self, display, shared_cache):
+        _, publisher, _ = display
+        _, web_cache, _ = shared_cache
+        publisher.tick()
+        publisher.cache_manager = MagicMock(wraps=publisher.cache_manager)
+
+        def reads():
+            return [c for c in publisher.cache_manager.get.call_args_list
+                    if c.args[0] == ERROR_CLEAR_REQUEST_KEY]
+
+        for _ in range(5):
+            publisher.tick()
+        assert reads() == []          # no file: a stat per tick, no read
+        errors.request_error_clear(web_cache, 1.0)
+        publisher.tick()
+        assert len(reads()) == 1
+        for _ in range(5):
+            publisher.tick()
+        assert len(reads()) == 1      # unchanged file: not read again
+        errors.request_error_clear(web_cache, 2.0)
+        publisher.tick()
+        assert len(reads()) == 2
+
+    def test_clear_now_publishes_what_it_applied(self, display, shared_cache):
+        aggregator, publisher, _ = display
+        _, web_cache, _ = shared_cache
+        _fail(aggregator)
+        assert publisher.clear_now("sock-1", datetime.now().timestamp() + 1) == 1
+        snapshot = web_cache.get(ERROR_SNAPSHOT_KEY, max_age=None, memory_ttl=0)
+        assert snapshot["applied_clear_id"] == "sock-1"
+        assert snapshot["total_errors"] == 0
+        assert snapshot["applied_clear_cutoff"] is not None
+
+    def test_the_handler_needs_a_running_publisher(self, monkeypatch):
+        from src.ipc.contract import ErrorsClearArgs
+        monkeypatch.setattr(errors, "_snapshot_publisher", None)
+        with pytest.raises(RuntimeError):
+            errors.apply_error_clear("x", ErrorsClearArgs(cutoff=1.0))
+
+
 @pytest.mark.skipif(not hasattr(os, "fchmod") or os.name == "nt",
                     reason="POSIX file modes")
 def test_both_files_are_group_readable(web, display, shared_cache):

test/test_espn_dates.py

@@ -489,3 +489,171 @@ class TestConcurrency:
 
         assert live["peak"] <= espn_dates.ESPN_CHUNK_WORKERS
         assert live["peak"] > 1, "chunks should actually overlap"
+
+
+class TestEdgeMonths:
+    """A window's partial edge months are asked whole and trimmed.
+
+    The default scoreboard window -- a fortnight either side of today -- spans
+    two partial months, so it used to cost 29 day requests per league. ESPN's
+    ``dates=YYYYMMDD`` means a US Eastern day (verified against the live API
+    on 2026-10-03, 417 of 417 soccer events), so a month answer trimmed to
+    the window's Eastern days is what the day requests returned.
+    """
+
+    def test_a_fortnight_either_side_is_two_requests(self):
+        planned = espn_dates.espn_request_chunks(date(2026, 9, 20), date(2026, 10, 18))
+        assert planned == [
+            ("202609", (date(2026, 9, 20), date(2026, 9, 30))),
+            ("202610", (date(2026, 10, 1), date(2026, 10, 18))),
+        ]
+
+    def test_a_live_polls_two_days_stay_two_days(self):
+        planned = espn_dates.espn_request_chunks(date(2026, 10, 2), date(2026, 10, 3))
+        assert planned == [("20261002", None), ("20261003", None)]
+
+    def test_the_threshold_is_inclusive(self):
+        n = espn_dates.ESPN_MONTH_COVER_MIN_DAYS
+        short = espn_dates.espn_request_chunks(date(2026, 10, 1), date(2026, 10, n - 1))
+        assert [chunk for chunk, _ in short] == [
+            "202610%02d" % day for day in range(1, n)]
+        enough = espn_dates.espn_request_chunks(date(2026, 10, 1), date(2026, 10, n))
+        assert enough == [("202610", (date(2026, 10, 1), date(2026, 10, n)))]
+
+    def test_whole_months_and_short_edges_are_unchanged(self):
+        planned = espn_dates.espn_request_chunks(date(2026, 8, 30), date(2026, 10, 2))
+        assert planned == [
+            ("20260830", None), ("20260831", None), ("202609", None),
+            ("20261001", None), ("20261002", None),
+        ]
+
+    def test_without_time_zone_data_edges_stay_days(self, monkeypatch):
+        monkeypatch.setattr(espn_dates, "_EASTERN", None)
+        planned = espn_dates.espn_request_chunks(date(2026, 9, 20), date(2026, 10, 18))
+        assert len(planned) == 29
+        assert all(trim is None for _, trim in planned)
+
+    @pytest.mark.parametrize("start,end", [
+        (date(2026, 9, 20), date(2026, 10, 18)),
+        (date(2026, 1, 25), date(2026, 3, 3)),
+        (date(2026, 12, 20), date(2027, 1, 9)),
+        (date(2026, 10, 5), date(2026, 10, 9)),
+    ])
+    def test_the_planned_requests_still_cover_every_day_exactly_once(self, start, end):
+        covered = []
+        for chunk, trim in espn_dates.espn_request_chunks(start, end):
+            if trim is None:
+                covered.extend(days_covered_by([chunk]))
+            else:
+                assert chunk == trim[0].strftime("%Y%m") == trim[1].strftime("%Y%m")
+                covered.extend(trim[0] + timedelta(days=offset)
+                               for offset in range((trim[1] - trim[0]).days + 1))
+        expected = [start + timedelta(days=offset) for offset in range((end - start).days + 1)]
+        assert covered == expected
+
+    def test_a_trimmed_month_keeps_only_the_windows_eastern_days(self):
+        september = [
+            # 03:30Z on the 20th is still the 19th in New York: outside.
+            {"id": "before", "date": "2026-09-20T03:30Z"},
+            {"id": "first", "date": "2026-09-20T14:00Z"},
+            {"id": "late", "date": "2026-09-30T23:30Z"},
+        ]
+        october = [
+            {"id": "oct1", "date": "2026-10-01T19:00Z"},
+            # 03:30Z on the 19th is the evening of the 18th in New York: inside.
+            {"id": "last", "date": "2026-10-19T03:30Z"},
+            {"id": "after", "date": "2026-10-19T14:00Z"},
+            {"id": "undated"},
+        ]
+        session = FakeSession({"202609": september, "202610": october})
+
+        data = fetch_espn_date_chunks(session, URL, params={"dates": "20260920-20261018"})
+
+        assert sorted(call["dates"] for call in session.calls) == ["202609", "202610"]
+        # An event with no readable date is kept, never dropped on a guess.
+        assert [e["id"] for e in data["events"]] == ["first", "late", "oct1", "last", "undated"]
+
+    def test_eastern_standard_time_is_honoured_after_the_clocks_change(self):
+        # 2026-11-01 ends daylight saving: Eastern is UTC-5 from then on.
+        november = [
+            {"id": "out", "date": "2026-11-15T04:30Z"},  # Nov 14, 23:30 EST
+            {"id": "in", "date": "2026-11-15T05:30Z"},   # Nov 15, 00:30 EST
+        ]
+        session = FakeSession({"202611": november})
+        data = fetch_espn_date_chunks(session, URL, params={"dates": "20261115-20261121"})
+        assert [e["id"] for e in data["events"]] == ["in"]
+
+    def test_a_capped_edge_month_re_asks_only_the_windows_days(self):
+        full = [{"id": "cap%d" % i, "date": "2026-10-05T18:00Z"} for i in range(ESPN_MAX_LIMIT)]
+        by_chunk = {"202610": full}
+        by_chunk.update({"202610%02d" % day: [{"id": "o%02d" % day}] for day in range(1, 32)})
+        session = FakeSession(by_chunk)
+
+        data = fetch_espn_date_chunks(session, URL, params={"dates": "20261001-20261010"})
+
+        sent = [call["dates"] for call in session.calls]
+        assert sent[0] == "202610"
+        assert sorted(sent[1:]) == ["202610%02d" % day for day in range(1, 11)]
+        assert [e["id"] for e in data["events"]] == ["o%02d" % day for day in range(1, 11)]
+
+
+class TestProcessWideChunkCap:
+    """The chunk cap holds across windows, not per window.
+
+    A soccer board starting eight leagues fetches sixteen windows at once.
+    With a pool of ``ESPN_CHUNK_WORKERS`` each, ~40 requests were in flight
+    and every one past a session's pool opened a connection -- and a DNS
+    lookup. On ledpi that was ~90 NameResolutionErrors per start.
+    """
+
+    def test_concurrent_windows_share_one_budget(self):
+        live = {"now": 0, "peak": 0}
+        guard = threading.Lock()
+
+        class CountingSession(FakeSession):
+            def get(self, url, params=None, headers=None, timeout=None):
+                with guard:
+                    live["now"] += 1
+                    live["peak"] = max(live["peak"], live["now"])
+                try:
+                    time.sleep(0.01)
+                    return super().get(url, params=params, headers=headers, timeout=timeout)
+                finally:
+                    with guard:
+                        live["now"] -= 1
+
+        sessions = [CountingSession() for _ in range(6)]
+        # Six leagues, so the fetch service cannot merge them into one, on a
+        # host with no token bucket: earlier tests may have spent ESPN's
+        # burst, and a bucket paced at 20/s would serialise these by itself.
+        threads = [
+            threading.Thread(target=fetch_espn_date_chunks,
+                             args=(session, "https://scores.example.test/league%d" % index),
+                             kwargs={"params": {"dates": "20260101-20261231"}})
+            for index, session in enumerate(sessions)
+        ]
+        for thread in threads:
+            thread.start()
+        for thread in threads:
+            thread.join(timeout=30)
+
+        assert all(len(session.calls) == 12 for session in sessions)
+        assert live["peak"] <= espn_dates.ESPN_CHUNK_WORKERS
+        assert live["peak"] > 1, "chunks should still overlap"
+
+
+def test_a_fresh_process_skips_the_doomed_range_request():
+    """Every start used to spend one 400 per window learning that ranges are
+    still rejected -- eleven at once from a soccer board. A new process now
+    starts inside the retry period instead."""
+    import subprocess
+    import sys
+    from pathlib import Path
+
+    out = subprocess.run(
+        [sys.executable, "-c",
+         "import src.common.espn_dates as e; print(e._ranges_known_rejected())"],
+        cwd=str(Path(__file__).resolve().parents[1]),
+        capture_output=True, text=True, timeout=60,
+    )
+    assert out.stdout.strip() == "True", out.stderr

test/test_fetch_service.py

@@ -576,6 +576,42 @@ class TestCounters:
         assert snap["hosts"]["site.api.espn.com"]["requests"] == 1
         assert snap["totals"]["bytes"] == 3 * len(b'{"ok": 1}')
 
+    def test_wire_bytes_are_the_compressed_size(self, service):
+        # Built the way requests builds a real response: a urllib3
+        # HTTPResponse carrying a gzip body, decoded when .content is read.
+        import gzip
+        import io
+
+        from requests.adapters import HTTPAdapter
+        from urllib3.response import HTTPResponse
+
+        decoded = json.dumps({"events": [{"id": str(i), "name": "x" * 200}
+                                         for i in range(50)]}).encode()
+        wire = gzip.compress(decoded)
+
+        def handler(url, kwargs):
+            raw = HTTPResponse(body=io.BytesIO(wire), status=200,
+                               headers={"Content-Encoding": "gzip",
+                                        "Content-Type": "application/json"},
+                               preload_content=False, decode_content=True)
+            request = requests.Request("GET", url).prepare()
+            response = HTTPAdapter().build_response(request, raw)
+            response.content  # what Session.get does for a non-streamed call
+            return response
+
+        response = service.get(FakeSession(handler), "https://site.api.espn.com/x")
+        assert response.content == decoded
+        totals = _counters(service)
+        assert totals["bytes"] == len(decoded)
+        assert totals["wire_bytes"] == len(wire) < len(decoded)
+
+    def test_wire_bytes_fall_back_to_the_decoded_size(self, service):
+        # No urllib3 response behind it (a test double, another adapter):
+        # count what is known rather than nothing.
+        service.get(FakeSession(), "https://api.test/x")
+        totals = _counters(service)
+        assert totals["wire_bytes"] == totals["bytes"] == len(b'{"ok": 1}')
+
     def test_errors_and_http_errors(self, service):
         def handler(url, kwargs):
             if url.endswith("/down"):
@@ -670,14 +706,14 @@ class TestCallerIdentity:
         assert _counters(global_service, plugin="football-scoreboard")["requests"] == 1
 
     def test_espn_chunks_on_worker_threads_count_against_the_caller(self, global_service):
-        from src.common.espn_dates import espn_date_chunks, fetch_espn_date_chunks, parse_espn_date_range
+        from src.common.espn_dates import espn_request_chunks, fetch_espn_date_chunks, parse_espn_date_range
 
         session = FakeSession(lambda url, kw: make_response(body=b'{"events": []}', url=url))
         dates = "20260801-20261015"
         with plugin_scope("baseball-scoreboard"):
             fetch_espn_date_chunks(session, "https://site.api.espn.com/s/scoreboard",
                                    params={"dates": dates})
-        chunks = len(espn_date_chunks(*parse_espn_date_range(dates)))
+        chunks = len(espn_request_chunks(*parse_espn_date_range(dates)))
         assert chunks > 1
         assert len(session.calls) == chunks
         assert _counters(global_service, plugin="baseball-scoreboard")["requests"] == chunks

test/test_font_manager.py

@@ -185,6 +185,149 @@ class TestPluginFonts:
         assert fm.font_catalog["my-plugin::bundled"] == str(plugin_dir / "fonts" / "Bundled.ttf")
 
 
+class TestForgetPluginFonts:
+    """forget_plugin_fonts drops what a plugin's manifest registered. Before
+    it, unloading a plugin left its fonts resolvable and its cached font
+    objects alive until a restart."""
+
+    @staticmethod
+    def _register(fm, root, plugin_id, family="bundled"):
+        plugin_dir = root / plugin_id
+        (plugin_dir / "fonts").mkdir(parents=True, exist_ok=True)
+        font_file = plugin_dir / "fonts" / f"{family}.ttf"
+        if not font_file.exists():  # a loaded font may hold it open (Windows)
+            shutil.copy(resolve_asset_path("assets/fonts/PressStart2P-Regular.ttf"), font_file)
+        manifest = {"fonts": [{"family": family, "source": f"plugin://fonts/{family}.ttf"}]}
+        assert fm.register_plugin_fonts(plugin_id, manifest, plugin_dir=plugin_dir)
+        return plugin_dir
+
+    @staticmethod
+    def _entries_of(fm, plugin_id):
+        prefix = f"{plugin_id}::"
+        return {
+            "plugin_fonts": plugin_id in fm.plugin_fonts,
+            "plugin_font_catalogs": plugin_id in fm.plugin_font_catalogs,
+            "font_catalog": [k for k in fm.font_catalog if k.startswith(prefix)],
+            "font_cache": [k for k in fm.font_cache if k.startswith(prefix)],
+        }
+
+    NONE = {"plugin_fonts": False, "plugin_font_catalogs": False,
+            "font_catalog": [], "font_cache": []}
+
+    def test_unload_leaves_no_plugin_entries(self, fm, tmp_path):
+        self._register(fm, tmp_path, "alpha")
+        fm.resolve_font("alpha.title", "bundled", 8, plugin_id="alpha")
+        fm.get_font("alpha::bundled", 10)
+        assert self._entries_of(fm, "alpha")["font_cache"]  # cached before
+        gen = fm.cache_generation
+
+        assert fm.forget_plugin_fonts("alpha") is True
+
+        assert self._entries_of(fm, "alpha") == self.NONE
+        assert fm.cache_generation == gen + 1
+        # The family no longer resolves to the plugin's file.
+        assert fm.font_catalog.get("alpha::bundled") is None
+
+    def test_other_plugins_and_core_fonts_are_untouched(self, fm, tmp_path):
+        self._register(fm, tmp_path, "alpha")
+        self._register(fm, tmp_path, "beta")
+        # A plugin whose id is a prefix of another's must not take it along.
+        self._register(fm, tmp_path, "alpha-two")
+        for pid in ("alpha", "beta", "alpha-two"):
+            fm.get_font(f"{pid}::bundled", 8)
+        core_font = fm.get_font("press_start", 8)
+        beta_before = self._entries_of(fm, "beta")
+        alpha_two_before = self._entries_of(fm, "alpha-two")
+
+        fm.forget_plugin_fonts("alpha")
+
+        assert self._entries_of(fm, "beta") == beta_before
+        assert self._entries_of(fm, "alpha-two") == alpha_two_before
+        assert fm.get_font("press_start", 8) is core_font
+
+    def test_reload_re_registers_cleanly(self, fm, tmp_path):
+        plugin_dir = self._register(fm, tmp_path, "alpha")
+        old = fm.get_font("alpha::bundled", 8)
+        fm.forget_plugin_fonts("alpha")
+
+        self._register(fm, tmp_path, "alpha")
+
+        assert fm.font_catalog["alpha::bundled"] == str(plugin_dir / "fonts" / "bundled.ttf")
+        font = fm.resolve_font("alpha.title", "bundled", 8, plugin_id="alpha")
+        assert isinstance(font, ImageFont.FreeTypeFont)
+        assert font is not old  # loaded fresh, not the dropped cache entry
+
+    def test_a_family_the_new_manifest_drops_stops_resolving(self, fm, tmp_path):
+        self._register(fm, tmp_path, "alpha", family="old_face")
+        fm.forget_plugin_fonts("alpha")
+        self._register(fm, tmp_path, "alpha", family="new_face")
+
+        assert "alpha::old_face" not in fm.font_catalog
+        assert "alpha::new_face" in fm.font_catalog
+
+    def test_unknown_plugin_is_a_no_op(self, fm):
+        catalog = dict(fm.font_catalog)
+        gen = fm.cache_generation
+
+        assert fm.forget_plugin_fonts("never-registered") is False
+
+        assert fm.font_catalog == catalog
+        assert fm.cache_generation == gen
+
+
+class TestPluginManagerReloadFonts:
+    """Through PluginManager: unloading a plugin forgets its manifest fonts,
+    and reload_plugin (unload + load) registers them again so they resolve."""
+
+    PLUGIN_ID = "font-reload-demo"
+    MODULE = "plugin_font_reload_demo"
+
+    def test_unload_forgets_and_reload_resolves(self, tmp_path):
+        import sys
+        from src.plugin_system.plugin_manager import PluginManager
+
+        plugins_dir = tmp_path / "plugins"
+        plugin_dir = plugins_dir / self.PLUGIN_ID
+        (plugin_dir / "fonts").mkdir(parents=True)
+        shutil.copy(resolve_asset_path("assets/fonts/PressStart2P-Regular.ttf"),
+                    plugin_dir / "fonts" / "Bundled.ttf")
+        manifest = {"id": self.PLUGIN_ID, "name": "Demo", "class_name": "Demo",
+                    "entry_point": "manager.py",
+                    "fonts": {"fonts": [{"family": "bundled",
+                                         "source": "plugin://fonts/Bundled.ttf"}]}}
+        (plugin_dir / "manifest.json").write_text(json.dumps(manifest), encoding="utf-8")
+        (plugin_dir / "manager.py").write_text(
+            "class Demo:\n"
+            "    def __init__(self, plugin_id, config, display_manager, cache_manager, plugin_manager):\n"
+            "        self.enabled = True\n", encoding="utf-8")
+
+        pm = PluginManager(plugins_dir=str(plugins_dir))
+        fm = FontManager({})
+        pm.font_manager = fm
+        pm.plugin_manifests[self.PLUGIN_ID] = manifest
+        key = f"{self.PLUGIN_ID}::bundled"
+        try:
+            assert pm.load_plugin(self.PLUGIN_ID) is True
+            assert key in fm.font_catalog
+            fm.register_manager_font(self.PLUGIN_ID, "demo.title", "bundled", 8)
+            old = fm.resolve_font("demo.title", "bundled", 8, plugin_id=self.PLUGIN_ID)
+
+            assert pm.unload_plugin(self.PLUGIN_ID) is True
+            assert self.PLUGIN_ID not in fm.plugin_fonts
+            assert self.PLUGIN_ID not in fm.plugin_font_catalogs
+            assert key not in fm.font_catalog
+            assert not [k for k in fm.font_cache if k.startswith(f"{self.PLUGIN_ID}::")]
+            assert self.PLUGIN_ID not in fm.manager_fonts
+
+            assert pm.reload_plugin(self.PLUGIN_ID) is True
+            assert fm.font_catalog[key] == str(plugin_dir / "fonts" / "Bundled.ttf")
+            font = fm.resolve_font("demo.title", "bundled", 8, plugin_id=self.PLUGIN_ID)
+            assert isinstance(font, ImageFont.FreeTypeFont)
+            assert font is not old
+        finally:
+            sys.modules.pop(self.MODULE, None)
+
+
 class TestDownloadFont:
     """_download_font: plugin fonts declared by URL, cached in temp_font_dir."""
 

test/test_handover_scroll_state.py

@@ -709,6 +709,6 @@ class TestTheControllersOwnScreens:
         c._check_wifi_status_message.return_value = None
         inputs = DisplayController._arbiter_inputs(c)
         assert inputs.wifi_notice is None
-        assert Arbiter.decide(ArbiterState(), inputs, 0.0).source is Source.LEGACY
+        assert Arbiter.decide(ArbiterState(), inputs, 0.0).source is Source.ROTATION
         assert dm.is_currently_scrolling()
         assert dm._frame_hold == 2

test/test_installed_list_registry_offline.py

@@ -0,0 +1,188 @@
+"""GET /api/v3/plugins/installed never waits on the network for registry data.
+
+The route used `get_registry_info`, which goes through `fetch_registry`: on a
+cold (or expired) cache that downloads plugins.json from GitHub with a 10s
+timeout and three attempts -- and, with no registry to fall back on, every
+plugin's lookup repeated the whole cycle. The first plugin-list load after a
+restart waited on GitHub, and offline it waited out every timeout.
+
+Now the route reads the registry copy already in memory, however old, and a
+missing or expired copy only starts a background refresh. These tests block
+the network at the socket layer (DNS lookups hang, then fail) and assert the
+request returns quickly without a single network attempt on the request path.
+"""
+
+import functools
+import socket
+import threading
+import time
+from unittest.mock import MagicMock
+
+import pytest
+import requests
+
+from test._api_v3_test_helpers import (  # noqa: F401 - fixtures
+    api_v3_client, api_v3_module,
+)
+from src.plugin_system.store_manager import PluginStoreManager
+
+# How long a blocked lookup hangs before failing: long enough that a single
+# one on the request path blows the response budget below.
+HANG_SECONDS = 1.5
+FAST_SECONDS = 1.0
+
+REGISTRY = {'plugins': [
+    {'id': 'weather', 'name': 'Weather', 'verified': True, 'latest_version': '1.2.0'},
+]}
+
+
+@pytest.fixture
+def blocked_network(monkeypatch):
+    """Every DNS lookup hangs, then fails; records the thread it came from."""
+    attempts = []
+
+    def hang_then_fail(host, *args, **kwargs):
+        attempts.append((host, threading.current_thread().name))
+        time.sleep(HANG_SECONDS)
+        raise socket.gaierror(-3, 'Temporary failure in name resolution (blocked by test)')
+
+    monkeypatch.setattr(socket, 'getaddrinfo', hang_then_fail)
+    return attempts
+
+
+@pytest.fixture
+def store(tmp_path, monkeypatch):
+    store = PluginStoreManager(plugins_dir=str(tmp_path / 'plugins'))
+    # One attempt, no pause between attempts, so a background refresh against
+    # the blocked network ends within the test (teardown joins it).
+    monkeypatch.setattr(store, '_http_get_with_retries', functools.partial(
+        PluginStoreManager._http_get_with_retries, store, max_retries=1))
+    yield store
+    thread = getattr(store, '_registry_refresh_thread', None)
+    if thread is not None:
+        thread.join(timeout=30)
+
+
+@pytest.fixture
+def get_installed(api_v3_module, api_v3_client, store, tmp_path):
+    api = api_v3_module.api_v3
+    api.plugin_store_manager = store
+    api.plugin_catalog.plugins_dir = str(tmp_path / 'plugins')
+    api.plugin_catalog.get_all_plugin_info = MagicMock(return_value=[
+        {'id': 'weather', 'name': 'Weather', 'version': '1.0.0'},
+        {'id': 'clock', 'name': 'Clock', 'version': '2.0.0'},
+    ])
+    api.plugin_catalog.get_plugin_display_modes = MagicMock(return_value=[])
+    api.config_manager.load_config = MagicMock(return_value={})
+
+    def _get():
+        start = time.perf_counter()
+        response = api_v3_client.get('/api/v3/plugins/installed')
+        elapsed = time.perf_counter() - start
+        assert response.status_code == 200
+        plugins = {p['id']: p for p in response.get_json()['data']['plugins']}
+        return plugins, elapsed
+    return _get
+
+
+def _request_path_attempts(attempts):
+    return [a for a in attempts if a[1] != 'registry-refresh']
+
+
+def test_a_cold_cache_offline_returns_fast_without_registry_info(get_installed, blocked_network):
+    plugins, elapsed = get_installed()
+
+    assert _request_path_attempts(blocked_network) == []
+    assert elapsed < FAST_SECONDS, f"installed list took {elapsed:.2f}s with the network blocked"
+    weather = plugins['weather']
+    assert weather['latest_version'] == ''
+    assert weather['update_available'] is False
+    assert weather['verified'] is False
+
+
+def test_a_stale_cache_is_used_as_is_without_a_fetch(get_installed, store, blocked_network):
+    store.registry_cache = REGISTRY
+    store.registry_cache_time = time.time() - store.registry_cache_timeout - 3600
+
+    plugins, elapsed = get_installed()
+
+    assert _request_path_attempts(blocked_network) == []
+    assert elapsed < FAST_SECONDS
+    weather = plugins['weather']
+    assert weather['latest_version'] == '1.2.0'
+    assert weather['update_available'] is True
+    assert weather['verified'] is True
+    assert plugins['clock']['latest_version'] == ''
+
+
+def test_a_fresh_cache_starts_no_refresh(get_installed, store, blocked_network):
+    store.registry_cache = REGISTRY
+    store.registry_cache_time = time.time()
+
+    plugins, _ = get_installed()
+
+    assert blocked_network == []
+    assert store._registry_refresh_thread is None
+    assert plugins['weather']['update_available'] is True
+
+
+def test_a_cold_cache_is_filled_in_the_background_for_the_next_load(get_installed, store, monkeypatch):
+    response = MagicMock()
+    response.json.return_value = REGISTRY
+    fetched_on = []
+
+    def fake_get(url, **kwargs):
+        fetched_on.append(threading.current_thread().name)
+        return response
+
+    monkeypatch.setattr(store, '_http_get_with_retries', fake_get)
+
+    first, _ = get_installed()
+    assert first['weather']['update_available'] is False
+    store._registry_refresh_thread.join(timeout=10)
+
+    second, _ = get_installed()
+    assert second['weather']['latest_version'] == '1.2.0'
+    assert second['weather']['update_available'] is True
+    # One background fetch for the whole listing, none on the request path.
+    assert fetched_on == ['registry-refresh']
+
+
+def test_an_offline_background_refresh_backs_off(store, monkeypatch):
+    def offline(url, **kwargs):
+        raise requests.ConnectionError('blocked by test')
+
+    monkeypatch.setattr(store, '_http_get_with_retries', offline)
+
+    assert store.refresh_registry_in_background() is True
+    store._registry_refresh_thread.join(timeout=10)
+    assert store.registry_cache is None
+    # Offline: the next page load does not start another attempt straight away.
+    assert store.refresh_registry_in_background() is False
+    store._registry_refresh_retry_after = 0.0
+    assert store.refresh_registry_in_background() is True
+
+
+def test_only_one_background_refresh_runs_at_a_time(store, monkeypatch):
+    release = threading.Event()
+
+    def slow(url, **kwargs):
+        release.wait(10)
+        raise requests.ConnectionError('blocked by test')
+
+    monkeypatch.setattr(store, '_http_get_with_retries', slow)
+    try:
+        assert store.refresh_registry_in_background() is True
+        assert store.refresh_registry_in_background() is False
+    finally:
+        release.set()
+
+
+def test_get_registry_info_still_fetches_for_the_store(store, monkeypatch):
+    """The store, install and update paths keep fetching a cold registry."""
+    response = MagicMock()
+    response.json.return_value = REGISTRY
+    monkeypatch.setattr(store, '_http_get_with_retries', MagicMock(return_value=response))
+
+    assert store.get_registry_info('weather')['latest_version'] == '1.2.0'
+    store._http_get_with_retries.assert_called_once()

test/test_ipc_contract.py

@@ -167,7 +167,8 @@ class TestOnDemandArgs:
     def test_every_command_has_an_argument_type(self, cmd):
         args = {Command.ON_DEMAND_START: {'plugin_id': 'p'},
                 Command.PLUGIN_RELOAD: {'plugin_id': 'p'},
-                Command.BRIGHTNESS_SET: {'brightness': 50}}.get(cmd, {})
+                Command.BRIGHTNESS_SET: {'brightness': 50},
+                Command.ERRORS_CLEAR: {'cutoff': 1790000000.0}}.get(cmd, {})
         c.parse_args(cmd, args)
 
     def test_hello_versions(self):

test/test_ipc_display_stage2.py

@@ -41,6 +41,15 @@ def _reload(plugin_id):
     return _command(Command.PLUGIN_RELOAD, PluginReloadArgs(plugin_id))
 
 
+def _screen(mode):
+    """A rotation screen of ``mode``, as the ScreenRunner hands it to the
+    1 Hz loop's frame wait."""
+    from src.display_arbiter import ArbiterState, rotation_plan
+    from src.screen_runner import Screen
+    plan = rotation_plan(ArbiterState(current_mode=mode))
+    return Screen(plan, plugin=None, accepts_display_mode=False, start=0.0)
+
+
 @pytest.fixture
 def dc(test_display_controller):
     c = test_display_controller
@@ -253,7 +262,8 @@ class TestRealTimeWake:
         dc.on_demand_active = False
         dc._activate_on_demand = MagicMock(
             side_effect=lambda request: setattr(dc, 'current_display_mode', 'weather'))
-        dc._wifi_notice_pending = MagicMock(return_value=False)
+        dc._wifi_notice_pending = MagicMock(return_value=False)   # the dwell's check
+        dc._read_wifi_notice = MagicMock(return_value=None)       # the frame wait's
         dc._tick_plugin_updates = MagicMock()
         dc._check_live_takeover = MagicMock()
         dc.cache_manager.get = MagicMock(return_value=None)
@@ -282,10 +292,10 @@ class TestRealTimeWake:
             dc.current_display_mode = 'clock'
             stamps = []
             t = self._post_later(server, self._start_line(f's{i}'), 0.05, stamps)
-            ended = dc._wait_frame_interval(1.0, 'clock')
+            ended = dc._wait_frame_interval(1.0, _screen('clock'))
             woke = time.monotonic()
             t.join()
-            assert ended is True
+            assert ended is not None
             latencies.append(woke - stamps[0])
         latencies.sort()
         print(f"static-screen wake latency: median {latencies[5] * 1000:.2f} ms, "
@@ -315,7 +325,7 @@ class TestRealTimeWake:
                            'args': {'brightness': 33}}).encode()
         started = time.monotonic()
         t = self._post_later(server, line, 0.1, stamps)
-        assert dc._wait_frame_interval(0.5, 'clock') is False
+        assert dc._wait_frame_interval(0.5, _screen('clock')) is None
         assert time.monotonic() - started >= 0.49
         t.join()
         dc.display_manager.set_brightness.assert_called_once_with(33)
@@ -323,7 +333,7 @@ class TestRealTimeWake:
     def test_without_a_socket_it_is_a_plain_sleep(self, dc):
         dc._control_server = None
         started = time.monotonic()
-        assert dc._wait_frame_interval(0.2, 'clock') is False
+        assert dc._wait_frame_interval(0.2, _screen('clock')) is None
         assert time.monotonic() - started >= 0.19
 
 

test/test_ipc_stage4.py

@@ -0,0 +1,509 @@
+"""Stage 4 of the control socket: the file mailboxes are only a fallback.
+
+* The client knows whether the display had the request (``ControlError.sent``)
+  and ``should_fall_back`` allows a mailbox write only when it did not, or
+  when the display is too old to know the command (the upgrade case).
+* ``errors.clear`` is answered on the connection thread by a handler the
+  display registers; a display without one answers like an older display.
+* The display looks at the on-demand mailbox once a second while the socket
+  is up (0.25 s without it), reads it only when its file changed, never
+  touches it for a socket command, and logs who still writes it.
+* ``CacheManager.file_signature`` / ``MailboxWatch`` make a look one stat().
+
+The web routes are covered in test_api_v3_on_demand_socket.py and
+test_error_snapshot_cross_process.py.
+"""
+
+import json
+import logging
+import os
+import socket
+import time
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from src.cache_manager import CacheManager, MailboxWatch
+from src.ipc import client
+from src.ipc import contract as c
+from src.ipc.contract import Command, ErrorsClearArgs, OnDemandStartArgs, ProtocolError
+from src.ipc.server import ControlServer, QueuedCommand
+
+MAILBOX = 'display_on_demand_request'
+
+
+# -- the client: was the request sent? ---------------------------------------------
+
+class FakeSock:
+    """Stands in for a connected socket in client._exchange."""
+
+    def __init__(self, replies=(), send_error=None, recv_error=None):
+        self.replies = list(replies)
+        self.send_error = send_error
+        self.recv_error = recv_error
+        self.sent = b''
+
+    def settimeout(self, _t):
+        pass
+
+    def sendall(self, data):
+        if self.send_error is not None:
+            raise self.send_error
+        self.sent += data
+
+    def recv(self, _n):
+        if self.recv_error is not None:
+            raise self.recv_error
+        return self.replies.pop(0) if self.replies else b''
+
+    def close(self):
+        pass
+
+
+def _reply(request_id, **body):
+    return (json.dumps(dict({'v': 1, 'id': request_id}, **body)) + '\n').encode()
+
+
+def _call(sock=None, connect_error=None, request_id='rid-1'):
+    with patch.object(client, 'socket_supported', return_value=True), \
+         patch.object(client, '_connect',
+                      side_effect=connect_error, return_value=sock):
+        return client.request(Command.PING, {}, request_id=request_id, paths=['/x.sock'])
+
+
+def _error(**kw):
+    with pytest.raises(client.ControlError) as e:
+        _call(**kw)
+    return e.value
+
+
+class TestSent:
+    def test_an_answer_is_returned(self):
+        assert _call(FakeSock([_reply('rid-1', ok=True, result={'pong': True})])) == {'pong': True}
+
+    @pytest.mark.parametrize('reason', ['no_socket', 'refused', 'timeout', 'busy'])
+    def test_a_failed_connect_was_not_sent(self, reason):
+        e = _error(connect_error=client.ControlError(reason))
+        assert e.reason == reason and e.sent is False
+        assert client.should_fall_back(e)
+
+    def test_a_send_that_timed_out_was_not_sent(self):
+        e = _error(sock=FakeSock(send_error=socket.timeout()))
+        assert e.reason == 'timeout' and e.sent is False
+        assert client.should_fall_back(e)
+
+    def test_silence_after_the_request_was_sent(self):
+        e = _error(sock=FakeSock(recv_error=socket.timeout()))
+        assert e.reason == 'timeout' and e.sent is True
+        assert not client.should_fall_back(e)
+
+    def test_a_hang_up_after_the_request_was_sent(self):
+        e = _error(sock=FakeSock([]))
+        assert e.reason == 'closed' and e.sent is True
+        assert not client.should_fall_back(e)
+
+    def test_a_garbled_reply(self):
+        e = _error(sock=FakeSock([b'not json\n']))
+        assert e.reason == 'bad_response' and e.sent is True
+        assert not client.should_fall_back(e)
+
+    @pytest.mark.parametrize('code', ['busy', 'invalid_args', 'internal', 'pending', 'failed'])
+    def test_a_display_error_with_an_id_was_sent(self, code):
+        sock = FakeSock([_reply('rid-1', ok=False, error={'code': code, 'message': 'x'})])
+        e = _error(sock=sock)
+        assert e.reason == code and e.sent is True
+        assert not client.should_fall_back(e)
+
+    @pytest.mark.parametrize('code', ['forbidden', 'busy'])
+    def test_a_refusal_at_the_door_was_not_sent(self, code):
+        # forbidden, or too many connections: answered before the request
+        # was read, so with no id.
+        sock = FakeSock([(json.dumps({'v': 1, 'id': None, 'ok': False,
+                                      'error': {'code': code, 'message': 'x'}}) + '\n').encode()])
+        e = _error(sock=sock)
+        assert e.reason == code and e.sent is False
+        assert client.should_fall_back(e)
+
+    @pytest.mark.parametrize('code', ['unknown_command', 'unsupported_version'])
+    def test_an_older_display_is_fallen_back_from(self, code):
+        sock = FakeSock([_reply('rid-1', ok=False, error={'code': code, 'message': 'x'})])
+        e = _error(sock=sock)
+        assert e.sent is True
+        assert client.should_fall_back(e)
+
+    def test_a_request_refused_locally_never_left(self):
+        with pytest.raises(client.ControlError) as e:
+            client.request(Command.ERRORS_CLEAR, {'cutoff': 'soon'}, paths=['/x.sock'])
+        assert e.value.reason == 'invalid_request' and e.value.sent is False
+        assert client.should_fall_back(e.value)
+
+    def test_a_client_bug_falls_back(self):
+        assert client.should_fall_back(RuntimeError('boom'))
+
+
+# -- errors.clear on the server ------------------------------------------------------
+
+def _line(cmd, args, rid='r1'):
+    return c.encode_message({'v': 1, 'id': rid, 'cmd': cmd, 'args': args})
+
+
+class TestErrorsClearOnTheServer:
+    def test_the_handler_answers_it(self, tmp_path):
+        seen = []
+
+        def handler(request_id, args):
+            seen.append((request_id, args))
+            return {'request_id': request_id, 'cutoff': args.cutoff, 'cleared': 4}
+
+        server = ControlServer(str(tmp_path / 's.sock'),
+                               handlers={Command.ERRORS_CLEAR: handler})
+        response = server.handle_line(_line(Command.ERRORS_CLEAR, {'cutoff': 123}))
+        assert response.ok and response.result == {'request_id': 'r1', 'cutoff': 123.0,
+                                                   'cleared': 4}
+        assert seen == [('r1', ErrorsClearArgs(cutoff=123.0))]
+        assert not server.has_pending   # not queued for the render thread
+
+    def test_a_display_without_a_handler_answers_like_an_older_one(self, tmp_path):
+        server = ControlServer(str(tmp_path / 's.sock'))
+        response = server.handle_line(_line(Command.ERRORS_CLEAR, {'cutoff': 1}))
+        assert not response.ok and response.error.code == c.ErrorCode.UNKNOWN_COMMAND
+
+    def test_only_direct_commands_take_a_handler(self, tmp_path):
+        server = ControlServer(str(tmp_path / 's.sock'),
+                               handlers={Command.ON_DEMAND_START: lambda *a: {}})
+        response = server.handle_line(_line(Command.ON_DEMAND_START, {'plugin_id': 'p'}))
+        assert response.ok and response.result['accepted'] is True   # still queued
+        assert server.has_pending
+
+    def test_a_handler_error_is_contained(self, tmp_path):
+        def boom(*_a):
+            raise ValueError('disk gone')
+
+        server = ControlServer(str(tmp_path / 's.sock'), handlers={Command.ERRORS_CLEAR: boom})
+        response = server.handle_line(_line(Command.ERRORS_CLEAR, {'cutoff': 1}))
+        assert response.error.code == c.ErrorCode.INTERNAL
+        assert 'disk gone' not in response.error.message
+
+    def test_a_handler_can_refuse_with_a_code(self, tmp_path):
+        def refuse(*_a):
+            raise ProtocolError(c.ErrorCode.BUSY, 'later')
+
+        server = ControlServer(str(tmp_path / 's.sock'), handlers={Command.ERRORS_CLEAR: refuse})
+        assert server.handle_line(
+            _line(Command.ERRORS_CLEAR, {'cutoff': 1})).error.code == c.ErrorCode.BUSY
+
+    @pytest.mark.parametrize('cutoff', ['1', None, True, float('inf'), -1])
+    def test_bad_cutoffs_are_refused(self, cutoff):
+        with pytest.raises(ProtocolError) as e:
+            ErrorsClearArgs.from_dict({'cutoff': cutoff})
+        assert e.value.code == c.ErrorCode.INVALID_ARGS
+
+    def test_hello_lists_it(self, tmp_path):
+        server = ControlServer(str(tmp_path / 's.sock'))
+        result = server.handle_line(_line(Command.HELLO, {'versions': [1]})).result
+        assert Command.ERRORS_CLEAR in result['commands']
+
+
+# -- the display's mailbox poll ------------------------------------------------------
+
+class SignedCache:
+    """The slice of CacheManager the poll uses, counting what it costs."""
+
+    def __init__(self):
+        self.data = {}
+        self.writes = 0
+        self.version = {}
+        self.reads = []
+        self.stats = 0
+        self.deletes = []
+        self.sets = []
+
+    def file_signature(self, key):
+        self.stats += 1
+        return (self.version[key], 0, 0) if key in self.data else None
+
+    def get(self, key, *a, **kw):
+        self.reads.append(key)
+        return self.data.get(key)
+
+    def set(self, key, value, *a, **kw):
+        self.sets.append(key)
+        self.data[key] = value
+        self.writes += 1
+        self.version[key] = self.writes
+
+    def delete(self, key):
+        self.deletes.append(key)
+        self.data.pop(key, None)
+
+
+class FakeServer:
+    def __init__(self):
+        self.commands = []
+
+    @property
+    def has_pending(self):
+        return bool(self.commands)
+
+    def drain(self):
+        out, self.commands = self.commands, []
+        return out
+
+
+class Clock:
+    def __init__(self):
+        self.t = 1000.0
+
+    def __call__(self):
+        return self.t
+
+
+@pytest.fixture
+def controller(test_display_controller, monkeypatch):
+    dc = test_display_controller
+    dc.cache_manager = SignedCache()
+    dc._activate_on_demand = MagicMock()
+    dc.on_demand_active = False
+    dc.on_demand_request_id = None
+    dc._last_on_demand_poll = None
+    dc._on_demand_mailbox = None
+    dc._mailbox_writers_logged = frozenset()
+    clock = Clock()
+    monkeypatch.setattr('src.display_controller.time.monotonic', clock)
+    dc.clock = clock
+    return dc
+
+
+def _post(dc, rid, action='start', **fields):
+    dc.cache_manager.set(MAILBOX, dict({'request_id': rid, 'action': action}, **fields))
+
+
+def _poll_for(dc, seconds, step=1 / 16):   # exact in binary: no drift past a floor
+    end = dc.clock.t + seconds
+    while dc.clock.t < end:
+        dc._poll_on_demand_requests()
+        dc.clock.t += step
+
+
+class TestMailboxCadence:
+    def test_without_a_socket_it_is_looked_at_every_quarter_second(self, controller):
+        controller._control_server = None
+        _poll_for(controller, 10.0)
+        assert 38 <= controller.cache_manager.stats <= 42
+
+    def test_with_a_socket_it_is_looked_at_once_a_second(self, controller):
+        controller._control_server = FakeServer()
+        _poll_for(controller, 10.0)
+        assert 9 <= controller.cache_manager.stats <= 11
+
+    def test_a_look_that_finds_nothing_reads_nothing(self, controller):
+        controller._control_server = FakeServer()
+        _poll_for(controller, 10.0)
+        assert controller.cache_manager.reads == []
+
+    def test_an_unchanged_mailbox_is_not_read_again(self, controller):
+        # An already-processed start the delete could not remove, say.
+        controller._control_server = FakeServer()
+        controller.cache_manager.delete = MagicMock()   # the file stays
+        _post(controller, 'once', plugin_id='clock')
+        _poll_for(controller, 10.0)
+        assert controller.cache_manager.reads.count(MAILBOX) <= 2   # the read + the re-check
+        controller._activate_on_demand.assert_called_once()
+
+    def test_a_mailbox_request_lands_within_a_second_with_the_socket_up(self, controller):
+        # The upgrade case the other way round: a new display, and a web
+        # interface (or a plugin) that still writes the mailbox.
+        controller._control_server = FakeServer()
+        controller._poll_on_demand_requests()
+        controller.clock.t += 0.1
+        _post(controller, 'old-web', plugin_id='clock')
+        posted = controller.clock.t
+        while not controller._activate_on_demand.called:
+            controller._poll_on_demand_requests()
+            controller.clock.t += 0.05
+            assert controller.clock.t - posted < 1.5
+        assert controller.clock.t - posted <= controller.MAILBOX_POLL_INTERVAL_WITH_SOCKET + 0.06
+        assert MAILBOX in controller.cache_manager.deletes   # consumed
+
+    def test_socket_commands_still_land_at_once(self, controller):
+        server = controller._control_server = FakeServer()
+        controller._poll_on_demand_requests()
+        server.commands.append(QueuedCommand('sock', Command.ON_DEMAND_START,
+                                             OnDemandStartArgs(plugin_id='clock'), time.time()))
+        controller._poll_on_demand_requests()   # inside the mailbox interval
+        controller._activate_on_demand.assert_called_once()
+
+
+class TestSocketCommandsLeaveTheMailboxAlone:
+    def test_a_socket_start_reads_and_deletes_no_mailbox(self, controller):
+        server = controller._control_server = FakeServer()
+        controller._poll_on_demand_requests()
+        before = list(controller.cache_manager.reads)
+        server.commands.append(QueuedCommand('s1', Command.ON_DEMAND_START,
+                                             OnDemandStartArgs(plugin_id='clock'), time.time()))
+        controller._poll_on_demand_requests()
+        controller._activate_on_demand.assert_called_once()
+        assert MAILBOX not in controller.cache_manager.reads[len(before):]
+        assert controller.cache_manager.deletes == []
+
+    def test_a_socket_stop_reads_and_deletes_no_mailbox(self, controller):
+        from src.ipc.contract import OnDemandStopArgs
+        controller.on_demand_active = True
+        controller._clear_on_demand = MagicMock()
+        server = controller._control_server = FakeServer()
+        server.commands.append(QueuedCommand('s2', Command.ON_DEMAND_STOP,
+                                             OnDemandStopArgs(), time.time()))
+        controller.clock.t += 5
+        controller._drain_control_commands()
+        controller._clear_on_demand.assert_called_once()
+        assert MAILBOX not in controller.cache_manager.reads
+        assert controller.cache_manager.deletes == []
+
+    def test_a_mailbox_copy_of_a_socket_command_is_dropped(self, controller):
+        # An older web interface timed out after the display queued the
+        # command, then wrote the mailbox too.
+        server = controller._control_server = FakeServer()
+        server.commands.append(QueuedCommand('both', Command.ON_DEMAND_START,
+                                             OnDemandStartArgs(plugin_id='clock'), time.time()))
+        controller._poll_on_demand_requests()
+        _post(controller, 'both', plugin_id='clock')
+        _poll_for(controller, 2.0)
+        controller._activate_on_demand.assert_called_once()
+        assert MAILBOX not in controller.cache_manager.data
+
+
+class TestDeprecationLog:
+    def test_each_mailbox_writer_is_logged_once(self, controller, caplog):
+        controller._control_server = FakeServer()
+        caplog.set_level(logging.INFO, logger='src.display_controller')
+        for i, plugin in enumerate(['on-air', 'on-air', 'pomodoro-timer']):
+            _post(controller, f'r{i}', plugin_id=plugin)
+            _poll_for(controller, 1.2)
+        lines = [r.getMessage() for r in caplog.records if 'file mailbox' in r.getMessage()]
+        assert len(lines) == 2
+        assert 'on-air' in lines[0] and 'pomodoro-timer' in lines[1]
+
+    def test_nothing_is_logged_without_a_socket(self, controller, caplog):
+        controller._control_server = None
+        caplog.set_level(logging.INFO, logger='src.display_controller')
+        _post(controller, 'r', plugin_id='on-air')
+        _poll_for(controller, 1.0)
+        controller._activate_on_demand.assert_called_once()
+        assert not [r for r in caplog.records if 'file mailbox' in r.getMessage()]
+
+
+# -- file_signature and MailboxWatch -------------------------------------------------
+
+@pytest.fixture
+def real_cache(tmp_path, monkeypatch):
+    monkeypatch.setattr(CacheManager, '_get_writable_cache_dir', lambda self: str(tmp_path))
+    cache = CacheManager()
+    yield cache
+    cache.stop_cleanup_thread()
+
+
+class TestFileSignature:
+    def test_absent_key(self, real_cache):
+        assert real_cache.file_signature('nothing') is None
+
+    def test_every_write_is_a_new_signature(self, real_cache):
+        seen = set()
+        for i in range(20):
+            # Same size each time, written as fast as possible.
+            real_cache.set(MAILBOX, {'request_id': f'r{i:02d}'})
+            sig = real_cache.file_signature(MAILBOX)
+            assert isinstance(sig, tuple)
+            seen.add(sig)
+        assert len(seen) == 20
+
+    def test_gone_after_a_delete(self, real_cache):
+        real_cache.set(MAILBOX, {'a': 1})
+        real_cache.delete(MAILBOX)
+        assert real_cache.file_signature(MAILBOX) is None
+
+
+class TestMailboxWatch:
+    def test_reads_once_per_write(self, real_cache):
+        watch = MailboxWatch(MAILBOX)
+        assert watch.changed(real_cache) is False       # no file
+        real_cache.set(MAILBOX, {'request_id': 'a'})
+        assert watch.changed(real_cache) is True
+        assert watch.changed(real_cache) is False
+        real_cache.set(MAILBOX, {'request_id': 'b'})
+        assert watch.changed(real_cache) is True
+
+    def test_forget_reads_again(self, real_cache):
+        watch = MailboxWatch(MAILBOX)
+        real_cache.set(MAILBOX, {'request_id': 'a'})
+        assert watch.changed(real_cache) is True
+        watch.forget()
+        assert watch.changed(real_cache) is True
+
+    def test_a_rewrite_after_a_delete_is_seen(self, real_cache):
+        watch = MailboxWatch(MAILBOX)
+        real_cache.set(MAILBOX, {'request_id': 'a'})
+        assert watch.changed(real_cache)
+        real_cache.delete(MAILBOX)
+        assert watch.changed(real_cache) is False
+        real_cache.set(MAILBOX, {'request_id': 'a'})
+        assert watch.changed(real_cache) is True
+
+    def test_a_cache_that_cannot_tell_is_read_every_time(self):
+        watch = MailboxWatch(MAILBOX)
+        assert watch.changed(MagicMock()) is True
+        assert watch.changed(MagicMock()) is True
+        assert watch.changed(object()) is True
+
+
+# -- end to end over a real socket ---------------------------------------------------
+
+@pytest.mark.skipif(not c.socket_supported(), reason='AF_UNIX sockets are Linux/macOS only')
+class TestOverTheSocket:
+    @pytest.fixture
+    def sock_path(self):
+        import shutil
+        import tempfile
+        d = tempfile.mkdtemp(prefix='lmipc-')
+        yield os.path.join(d, 'control.sock')
+        shutil.rmtree(d, ignore_errors=True)
+
+    def test_errors_clear_round_trip(self, sock_path):
+        def handler(request_id, args):
+            return {'request_id': request_id, 'cutoff': args.cutoff, 'cleared': 2}
+
+        server = ControlServer(sock_path, handlers={Command.ERRORS_CLEAR: handler})
+        assert server.start()
+        try:
+            result = client.errors_clear('clr-1', 1790000000.0, paths=[sock_path])
+            assert result == {'request_id': 'clr-1', 'cutoff': 1790000000.0, 'cleared': 2}
+        finally:
+            server.close()
+
+    def test_an_older_display_is_an_upgrade_fallback(self, sock_path):
+        server = ControlServer(sock_path)   # no errors.clear handler
+        assert server.start()
+        try:
+            with pytest.raises(client.ControlError) as e:
+                client.errors_clear('clr-2', 1.0, paths=[sock_path])
+            assert e.value.reason == 'unknown_command' and e.value.sent is True
+            assert client.should_fall_back(e.value)
+        finally:
+            server.close()
+
+    def test_no_display_is_a_fallback(self, sock_path):
+        with pytest.raises(client.ControlError) as e:
+            client.errors_clear('clr-3', 1.0, paths=[sock_path])
+        assert e.value.reason == 'no_socket' and e.value.sent is False
+        assert client.should_fall_back(e.value)
+
+    def test_a_full_queue_is_not_a_fallback(self, sock_path):
+        server = ControlServer(sock_path, queue_size=1)
+        assert server.start()
+        try:
+            client.on_demand_start('q1', 'clock', None, paths=[sock_path])
+            with pytest.raises(client.ControlError) as e:
+                client.on_demand_start('q2', 'clock', None, paths=[sock_path])
+            assert e.value.reason == 'busy' and e.value.sent is True
+            assert not client.should_fall_back(e.value)
+        finally:
+            server.close()

test/test_malloc_tuning.py

@@ -0,0 +1,206 @@
+"""src/malloc_tuning.py: glibc arena cap and periodic malloc_trim, ctypes mocked."""
+import ctypes
+from pathlib import Path
+from unittest import mock
+
+import pytest
+
+from src import malloc_tuning as mt
+
+
+class FakeLibc:
+    """Stands in for ctypes.CDLL(None) on glibc: records calls."""
+
+    def __init__(self, trim_result=1, glibc=True):
+        self.trims = []
+        self.mallopts = []
+        self._trim_result = trim_result
+        if glibc:
+            self.gnu_get_libc_version = lambda: b'2.41'
+        self.malloc_trim = mock.Mock(side_effect=self._trim)
+        self.mallopt = mock.Mock(side_effect=self._mallopt)
+
+    def _trim(self, pad):
+        self.trims.append(pad)
+        if isinstance(self._trim_result, Exception):
+            raise self._trim_result
+        return self._trim_result
+
+    def _mallopt(self, param, value):
+        self.mallopts.append((param, value))
+        return 1
+
+
+@pytest.fixture(autouse=True)
+def fresh_libc(monkeypatch):
+    """Each test loads the C library itself; nothing real is called."""
+    monkeypatch.setattr(mt, '_libc', mt._UNLOADED)
+    monkeypatch.delenv('MALLOC_ARENA_MAX', raising=False)
+    yield
+
+
+def _on_glibc(monkeypatch, libc):
+    monkeypatch.setattr(mt.sys, 'platform', 'linux')
+    cdll = mock.Mock(return_value=libc)
+    monkeypatch.setattr(mt.ctypes, 'CDLL', cdll)
+    return cdll
+
+
+class Clock:
+    def __init__(self, t=1000.0):
+        self.t = t
+
+    def __call__(self):
+        return self.t
+
+
+# -- loading ----------------------------------------------------------------
+
+@pytest.mark.parametrize('platform', ['win32', 'darwin', 'freebsd14'])
+def test_not_linux_loads_nothing(monkeypatch, platform):
+    monkeypatch.setattr(mt.sys, 'platform', platform)
+    cdll = mock.Mock(side_effect=AssertionError('must not load'))
+    monkeypatch.setattr(mt.ctypes, 'CDLL', cdll)
+    assert mt._load_libc() is None
+    assert mt.cap_arenas() is False
+    trimmer = mt.MallocTrimmer(interval=0)
+    assert not trimmer.available
+    assert trimmer.maybe_trim() is False
+    cdll.assert_not_called()
+
+
+def test_linux_without_glibc_is_a_noop(monkeypatch):
+    """musl: no gnu_get_libc_version (and no malloc_trim) -- nothing is called."""
+    libc = FakeLibc(glibc=False)
+    del libc.malloc_trim
+    _on_glibc(monkeypatch, libc)
+    assert mt._load_libc() is None
+    assert mt.cap_arenas() is False
+    assert mt.MallocTrimmer(interval=0).maybe_trim() is False
+    assert libc.mallopts == []
+
+
+def test_cdll_failure_is_a_noop(monkeypatch):
+    monkeypatch.setattr(mt.sys, 'platform', 'linux')
+    monkeypatch.setattr(mt.ctypes, 'CDLL', mock.Mock(side_effect=OSError('no libc')))
+    assert mt._load_libc() is None
+    assert mt.cap_arenas() is False
+
+
+def test_loads_once(monkeypatch):
+    cdll = _on_glibc(monkeypatch, FakeLibc())
+    mt._load_libc()
+    mt._load_libc()
+    mt.MallocTrimmer()
+    assert cdll.call_count == 1
+
+
+def test_declares_c_signatures(monkeypatch):
+    libc = FakeLibc()
+    _on_glibc(monkeypatch, libc)
+    mt._load_libc()
+    assert libc.malloc_trim.argtypes == [ctypes.c_size_t]
+    assert libc.mallopt.argtypes == [ctypes.c_int, ctypes.c_int]
+
+
+# -- cap_arenas ---------------------------------------------------------------
+
+def test_cap_arenas_calls_mallopt(monkeypatch):
+    libc = FakeLibc()
+    _on_glibc(monkeypatch, libc)
+    assert mt.cap_arenas() is True
+    assert libc.mallopts == [(mt.M_ARENA_MAX, 2)]
+    assert mt.M_ARENA_MAX == -8  # glibc's malloc.h
+
+
+def test_cap_arenas_defers_to_the_environment(monkeypatch):
+    libc = FakeLibc()
+    _on_glibc(monkeypatch, libc)
+    monkeypatch.setenv('MALLOC_ARENA_MAX', '4')
+    assert mt.cap_arenas() is False
+    assert libc.mallopts == []
+
+
+def test_cap_arenas_swallows_errors(monkeypatch):
+    libc = FakeLibc()
+    libc.mallopt = mock.Mock(side_effect=RuntimeError('boom'))
+    _on_glibc(monkeypatch, libc)
+    assert mt.cap_arenas() is False
+
+
+def test_cap_arenas_matches_the_unit():
+    """The in-process default is the value the unit's MALLOC_ARENA_MAX carries."""
+    unit = (Path(__file__).resolve().parent.parent / 'systemd' / 'ledmatrix.service').read_text()
+    assert f'Environment=MALLOC_ARENA_MAX={mt.DEFAULT_ARENA_MAX}\n' in unit
+
+
+# -- MallocTrimmer ------------------------------------------------------------
+
+def test_trim_waits_one_interval_then_rate_limits(monkeypatch):
+    libc = FakeLibc()
+    _on_glibc(monkeypatch, libc)
+    clock = Clock()
+    trimmer = mt.MallocTrimmer(interval=300, clock=clock)
+    assert trimmer.available
+    assert trimmer.maybe_trim() is False          # start-up: not yet
+    clock.t += 299.9
+    assert trimmer.maybe_trim() is False
+    clock.t += 0.1
+    assert trimmer.maybe_trim() is True
+    assert libc.trims == [0]
+    clock.t += 100
+    assert trimmer.maybe_trim() is False          # rate-limited
+    clock.t += 200
+    assert trimmer.maybe_trim() is True
+    assert libc.trims == [0, 0]
+
+
+def test_trim_reports_nothing_released(monkeypatch):
+    libc = FakeLibc(trim_result=0)
+    _on_glibc(monkeypatch, libc)
+    clock = Clock()
+    trimmer = mt.MallocTrimmer(interval=10, clock=clock)
+    clock.t += 10
+    assert trimmer.maybe_trim() is False
+    assert libc.trims == [0]
+
+
+def test_trim_failure_disables_trimming(monkeypatch):
+    libc = FakeLibc(trim_result=RuntimeError('boom'))
+    _on_glibc(monkeypatch, libc)
+    clock = Clock()
+    trimmer = mt.MallocTrimmer(interval=10, clock=clock)
+    clock.t += 10
+    assert trimmer.maybe_trim() is False
+    clock.t += 10
+    assert trimmer.maybe_trim() is False
+    assert libc.trims == [0]                      # not retried
+    assert not trimmer.available
+
+
+# -- wiring -------------------------------------------------------------------
+
+def test_run_py_caps_arenas_before_threads():
+    """run.py applies the cap before the watchdog or the controller import."""
+    src = (Path(__file__).resolve().parent.parent / 'run.py').read_text()
+    cap = src.index('malloc_tuning.cap_arenas()')
+    assert cap < src.index('display_watchdog.watchdog.begin_startup()')
+    assert cap < src.index('from src.display_controller import main')
+
+
+def test_render_loop_trims_between_screens():
+    src = (Path(__file__).resolve().parent.parent / 'src' / 'display_controller.py').read_text()
+    loop = src.index('display_watchdog.watchdog.loop_pass()')
+    trim = src.index('trimmer.maybe_trim()')
+    assert loop < trim < src.index('outcome = runner.run(plan, manager_to_display)')
+
+
+@pytest.mark.skipif(not mt.sys.platform.startswith('linux'), reason='glibc only')
+def test_real_libc_on_linux():
+    """On a real Linux C library the calls go through without raising."""
+    if mt._load_libc() is None:
+        pytest.skip('not glibc')
+    trimmer = mt.MallocTrimmer(interval=0)
+    assert trimmer.available
+    assert trimmer.maybe_trim() in (True, False)
+    assert trimmer.available  # did not fail and disable itself

test/test_on_demand_live_and_restore.py

@@ -0,0 +1,164 @@
+"""Two on-demand edges seen on a rig.
+
+  * A request naming a ``*_live`` mode got HTTP 200 and a different mode on
+    the panel. The session's mode list kept live modes only when the plugin's
+    has_live_content() said so, and that is the live-priority question,
+    which the sports plugins answer for favourite teams only: fifteen college
+    games on, no favourite playing, and ``ncaa_fb_live`` became
+    ``nfl_recent``.
+  * A restart during a session whose plugin then failed to load (its config
+    no longer validated) logged "No valid display modes found ... after
+    restoration" and left the session active with no modes: published as
+    active for a plugin that was not running, with its cached request kept
+    for the next restart.
+"""
+
+from unittest.mock import MagicMock
+
+import pytest
+
+SPORTS_MODES = ['nfl_live', 'nfl_recent', 'nfl_upcoming',
+                'ncaa_fb_live', 'ncaa_fb_recent', 'ncaa_fb_upcoming']
+
+
+def _sports_plugin(has_live_content=False):
+    plugin = MagicMock(spec=['display', 'has_live_content', 'has_live_priority',
+                             'get_live_modes'])
+    plugin.has_live_content.return_value = has_live_content
+    plugin.has_live_priority.return_value = True
+    plugin.get_live_modes.return_value = []
+    return plugin
+
+
+def _register(controller, plugin_id, modes, plugin):
+    controller.plugin_display_modes[plugin_id] = list(modes)
+    for mode in modes:
+        controller.plugin_modes[mode] = plugin
+        controller.mode_to_plugin_id[mode] = plugin_id
+        if mode not in controller.available_modes:
+            controller.available_modes.append(mode)
+
+
+@pytest.fixture
+def football(test_display_controller):
+    c = test_display_controller
+    _register(c, 'football-scoreboard', SPORTS_MODES, _sports_plugin())
+    return c
+
+
+class TestANamedLiveModeIsShown:
+
+    def test_it_is_the_first_screen(self, football):
+        football._activate_on_demand({'plugin_id': 'football-scoreboard',
+                                      'mode': 'ncaa_fb_live'})
+        assert football.on_demand_active
+        assert football.current_display_mode == 'ncaa_fb_live'
+        assert football.on_demand_mode == 'ncaa_fb_live'
+
+    def test_the_plugins_other_modes_follow_it(self, football):
+        football._activate_on_demand({'plugin_id': 'football-scoreboard',
+                                      'mode': 'ncaa_fb_live'})
+        assert football.on_demand_modes[0] == 'ncaa_fb_live'
+        assert set(football.on_demand_modes[1:]) == {
+            'nfl_recent', 'nfl_upcoming', 'ncaa_fb_recent', 'ncaa_fb_upcoming'}
+
+    def test_pinned_holds_it(self, football):
+        football._activate_on_demand({'plugin_id': 'football-scoreboard',
+                                      'mode': 'ncaa_fb_live', 'pinned': True})
+        assert football.on_demand_modes == ['ncaa_fb_live']
+
+    def test_a_bare_plugin_request_still_skips_quiet_live_modes(self, football):
+        """Only a mode asked for by name is kept: a plugin-only request
+        resolves to the plugin's first mode (nfl_live), and opening on an
+        empty live screen there is what the ordering exists to avoid."""
+        football._activate_on_demand({'plugin_id': 'football-scoreboard'})
+        assert not any(m.endswith('_live') for m in football.on_demand_modes)
+
+    def test_a_named_second_live_mode_with_content_leads(self, test_display_controller):
+        """With live content both live modes are kept, nfl_live first; a
+        request naming ncaa_fb_live must still open on it, not rotate away."""
+        c = test_display_controller
+        _register(c, 'football-scoreboard', SPORTS_MODES, _sports_plugin(has_live_content=True))
+        c._activate_on_demand({'plugin_id': 'football-scoreboard', 'mode': 'ncaa_fb_live'})
+        assert c.on_demand_modes[0] == 'ncaa_fb_live'
+        assert c.on_demand_modes.count('ncaa_fb_live') == 1
+        assert 'nfl_live' in c.on_demand_modes[1:]
+
+    def test_the_named_mode_survives_a_restart(self, football):
+        football._activate_on_demand({'plugin_id': 'football-scoreboard',
+                                      'mode': 'ncaa_fb_live'})
+        # The last on-demand config write, not the last write of any key: the
+        # font-usage publisher thread writes its own key at its own pace.
+        saved = [c for c in football.cache_manager.set.call_args_list
+                 if c.args and c.args[0] == 'display_on_demand_config'][-1]
+        config = saved.args[1]
+        assert config['named_mode'] == 'ncaa_fb_live'
+
+        football._reset_on_demand_fields()
+        football._select_startup_plugins(['football-scoreboard'], config)
+        football._populate_on_demand_modes_from_plugin()
+        assert football.on_demand_modes[football.on_demand_mode_index] == 'ncaa_fb_live'
+
+
+class TestARestoreWithNothingToResume:
+
+    @pytest.fixture
+    def restored(self, test_display_controller):
+        c = test_display_controller
+        c.config['clock-simple'] = {'enabled': True}
+        c._select_startup_plugins(['clock-simple'],
+                                  {'plugin_id': 'clock-simple', 'mode': 'clock-simple'})
+        assert c.on_demand_active
+        # The plugin's load then fails: nothing is registered for it.
+        c.cache_manager.clear_cache.reset_mock()
+        c._populate_on_demand_modes_from_plugin()
+        return c
+
+    def test_the_session_ends(self, restored):
+        assert not restored.on_demand_active
+        assert restored.on_demand_plugin_id is None
+        assert not restored.on_demand_schedule_override
+
+    def test_it_is_reported_as_an_error(self, restored):
+        assert restored.on_demand_status == 'error'
+        assert restored.on_demand_last_error == 'restore-failed'
+        # The last on-demand state write, not the last write of any key: the
+        # font-usage publisher thread writes its own key at its own pace.
+        published = [c for c in restored.cache_manager.set.call_args_list
+                     if c.args and c.args[0] == 'display_on_demand_state'][-1]
+        assert published.args[1]['status'] == 'error'
+        assert published.args[1]['error'] == 'restore-failed'
+
+    def test_the_cached_request_is_dropped(self, restored):
+        restored.cache_manager.clear_cache.assert_any_call('display_on_demand_config')
+
+
+def test_a_plugin_system_failure_ends_a_cached_session_not_yet_restored(
+        mock_config_manager, mock_display_manager, mock_cache_manager,
+        test_config_with_plugins, emulator_mode):
+    """Initialization can fail before the cached session is read, with
+    on_demand_active still False: the session must still end, visibly."""
+    from unittest.mock import patch
+    from src.display_controller import DisplayController
+
+    mock_config_manager.get_config.return_value = test_config_with_plugins
+    mock_config_manager.load_config.return_value = test_config_with_plugins
+    mock_cache_manager._memory_cache['display_on_demand_config'] = {
+        'plugin_id': 'clock-simple', 'mode': 'clock-simple'}
+    with patch('src.display_controller.ConfigManager', return_value=mock_config_manager), \
+         patch('src.display_controller.DisplayManager', return_value=mock_display_manager), \
+         patch('src.display_controller.CacheManager', return_value=mock_cache_manager), \
+         patch('src.display_controller.FontManager'), \
+         patch('src.plugin_system.PluginManager', side_effect=RuntimeError("boom")):
+        controller = DisplayController()
+        try:
+            assert controller.plugin_manager is None
+            assert not controller.on_demand_active
+            assert controller.on_demand_status == 'error'
+            assert controller.on_demand_last_error == 'restore-failed'
+            mock_cache_manager.clear_cache.assert_any_call('display_on_demand_config')
+        finally:
+            try:
+                controller.cleanup()
+            except Exception:
+                pass

test/test_plugin_manager_failed_load_cleanup.py

@@ -69,6 +69,7 @@ def test_fixed_plugin_loads_new_code_after_failed_load(plugin_env, first_source)
     assert MODULE_NAME not in sys.modules
     assert PLUGIN_ID not in pm.plugin_loader._loaded_modules
     pm.font_manager.forget_manager_fonts.assert_called_with(PLUGIN_ID)
+    pm.font_manager.forget_plugin_fonts.assert_called_with(PLUGIN_ID)
 
     (plugin_dir / "manager.py").write_text(_FIXED, encoding="utf-8")
     assert pm.load_plugin(PLUGIN_ID) is True

test/test_plugin_on_demand_api.py

@@ -0,0 +1,418 @@
+"""Plugins asking for the screen in-process: BasePlugin.request_on_demand()
+and end_on_demand().
+
+A plugin running in the display process used to write the
+``display_on_demand_request`` mailbox, which the display reads once a second
+while the control socket is up. These tests pin the way in that replaces it:
+
+* BasePlugin -> PluginManager -> DisplayController.submit_plugin_on_demand,
+  which only queues, from any thread;
+* the render thread applies the queue where it applies socket commands,
+  through the mailbox's own handler, without the mailbox's read floor, and
+  woken by the control socket when it is up;
+* a plugin's stop ends only its own session;
+* no display to ask (the web interface's plugin manager, an old core's
+  plugin manager) answers None, which is a plugin's cue to fall back to the
+  mailbox;
+* the mailbox still works for plugins that write it.
+"""
+
+import logging
+import threading
+import time
+from unittest.mock import MagicMock
+
+import pytest
+
+from src.ipc.server import ControlServer
+from src.plugin_system.base_plugin import BasePlugin
+from src.plugin_system.plugin_manager import PluginManager
+
+
+class _Plugin(BasePlugin):
+    def update(self):
+        pass
+
+    def display(self, force_clear=False):
+        pass
+
+
+def _plugin(plugin_id, manager):
+    plugin = _Plugin.__new__(_Plugin)
+    plugin.plugin_id = plugin_id
+    plugin.plugin_manager = manager
+    return plugin
+
+
+def _manager(handler=None):
+    manager = PluginManager.__new__(PluginManager)
+    manager.logger = logging.getLogger('test.plugin_on_demand')
+    if handler is not None:
+        manager.set_on_demand_handler(handler)
+    return manager
+
+
+class _WakeServer:
+    """The parts of ControlServer the controller uses, with no socket."""
+
+    def __init__(self):
+        self.woken = 0
+        self.has_pending = False
+
+    def wake(self):
+        self.woken += 1
+        self.has_pending = True
+
+    def drain(self):
+        self.has_pending = False
+        return []
+
+
+@pytest.fixture
+def controller(test_display_controller):
+    c_ = test_display_controller
+    c_.on_demand_active = False
+    c_.on_demand_request_id = None
+    c_._last_on_demand_poll = None
+    mailbox = {'value': None}
+
+    def fake_get(key, *a, **kw):
+        if key == 'display_on_demand_request':
+            return mailbox['value']
+        return None
+
+    c_.cache_manager.get = MagicMock(side_effect=fake_get)
+    c_.cache_manager.set = MagicMock()
+    c_.cache_manager.delete = MagicMock()
+    c_._activate_on_demand = MagicMock()
+    c_.mailbox = mailbox
+    return c_
+
+
+@pytest.fixture
+def wired(controller):
+    """A real PluginManager wired to the controller, as __init__ wires it."""
+    manager = _manager(controller.submit_plugin_on_demand)
+    return controller, manager
+
+
+class TestWiring:
+    def test_the_controller_wires_its_plugin_manager(self, controller):
+        controller.plugin_manager.set_on_demand_handler.assert_called_once_with(
+            controller.submit_plugin_on_demand)
+
+    def test_a_start_reaches_the_mailbox_handler(self, wired):
+        controller, manager = wired
+        rid = _plugin('pomodoro-timer', manager).request_on_demand(
+            mode='pomodoro', duration=30, pinned=True)
+        assert isinstance(rid, str) and rid
+        controller._activate_on_demand.assert_not_called()   # only queued
+        controller._poll_on_demand_requests()
+        controller._activate_on_demand.assert_called_once()
+        request = controller._activate_on_demand.call_args.args[0]
+        assert request['request_id'] == rid
+        assert request['action'] == 'start'
+        assert request['plugin_id'] == 'pomodoro-timer'
+        assert request['mode'] == 'pomodoro'
+        assert request['duration'] == 30.0 and request['pinned'] is True
+        assert request['source'] == 'plugin'
+        assert controller.on_demand_request_id == rid
+
+    def test_a_plugin_request_never_touches_the_mailbox(self, wired):
+        controller, manager = wired
+        _plugin('on-air', manager).request_on_demand(mode='on_air')
+        controller._drain_control_commands()
+        controller._activate_on_demand.assert_called_once()
+        mailbox_reads = [call for call in controller.cache_manager.get.call_args_list
+                         if call.args[0] == 'display_on_demand_request']
+        assert mailbox_reads == []
+        controller.cache_manager.delete.assert_not_called()
+
+    def test_requests_apply_in_order(self, wired):
+        controller, manager = wired
+        seen = []
+        controller._activate_on_demand = MagicMock(
+            side_effect=lambda r: seen.append(r['mode']))
+        plugin = _plugin('p', manager)
+        for mode in ('a', 'b', 'c'):
+            plugin.request_on_demand(mode=mode)
+        controller._poll_on_demand_requests()
+        assert seen == ['a', 'b', 'c']
+
+    def test_the_mailbox_still_works_for_older_plugins(self, wired):
+        controller, manager = wired
+        controller.mailbox['value'] = {'request_id': 'mb', 'action': 'start',
+                                       'plugin_id': 'birdnet-go'}
+        _plugin('on-air', manager).request_on_demand()
+        controller._poll_on_demand_requests()
+        ids = [call.args[0]['request_id'] for call in controller._activate_on_demand.call_args_list]
+        assert 'mb' in ids and len(ids) == 2
+
+    def test_a_failing_request_is_contained(self, wired):
+        controller, manager = wired
+        calls = []
+
+        def activate(request):
+            calls.append(request['mode'])
+            if request['mode'] == 'bad':
+                raise RuntimeError('plugin exploded')
+
+        controller._activate_on_demand = MagicMock(side_effect=activate)
+        plugin = _plugin('p', manager)
+        plugin.request_on_demand(mode='bad')
+        plugin.request_on_demand(mode='good')
+        controller._poll_on_demand_requests()
+        assert calls == ['bad', 'good']
+
+
+class TestPromptness:
+    def test_a_plugin_request_skips_the_pending_changes_floor(self, wired):
+        controller, manager = wired
+        controller._control_server = None
+        controller._service_pending_changes()
+        _plugin('p', manager).request_on_demand()
+        controller._service_pending_changes()        # well inside the 0.25 s floor
+        controller._activate_on_demand.assert_called_once()
+
+    def test_a_plugin_request_skips_the_mailbox_floor(self, wired):
+        controller, manager = wired
+        controller._control_server = _WakeServer()
+        controller._poll_on_demand_requests()        # sets the 1 s mailbox floor
+        _plugin('p', manager).request_on_demand()
+        controller._poll_on_demand_requests()
+        controller._activate_on_demand.assert_called_once()
+
+    def test_it_wakes_the_control_socket_wait(self, wired):
+        controller, manager = wired
+        server = ControlServer('/nonexistent/control.sock')   # never started
+        controller._control_server = server
+        assert not server.wait_for_command(0)
+        _plugin('p', manager).request_on_demand()
+        assert server.has_pending
+        assert controller._wait_for_control(5.0) is True     # returns at once
+        assert controller._control_command_pending()
+        controller._poll_on_demand_requests()
+        controller._activate_on_demand.assert_called_once()
+        assert not server.has_pending
+        assert not controller._control_command_pending()
+
+    def test_without_a_socket_a_waiting_request_cuts_the_sleep(self, wired):
+        controller, manager = wired
+        controller._control_server = None
+        _plugin('p', manager).request_on_demand()
+        started = time.monotonic()
+        assert controller._wait_for_control(5.0) is True
+        assert time.monotonic() - started < 1.0
+        assert controller._control_command_pending()
+
+    def test_nothing_waiting_keeps_the_floor(self, controller):
+        controller._control_server = None
+        controller._poll_on_demand_requests = MagicMock()
+        controller._service_pending_changes()
+        controller._service_pending_changes()
+        assert controller._poll_on_demand_requests.call_count == 1
+
+
+class TestThreads:
+    def test_requests_from_many_threads_all_land_in_order_per_thread(self, wired):
+        controller, manager = wired
+        seen = []
+        controller._activate_on_demand = MagicMock(
+            side_effect=lambda r: seen.append(r['mode']))
+        controller.PLUGIN_ON_DEMAND_QUEUE_SIZE = 10_000
+        threads_n, each = 8, 50
+        barrier = threading.Barrier(threads_n)
+
+        def ask(n):
+            plugin = _plugin(f'p{n}', manager)
+            barrier.wait()
+            for i in range(each):
+                assert plugin.request_on_demand(mode=f'{n}:{i}')
+
+        threads = [threading.Thread(target=ask, args=(n,)) for n in range(threads_n)]
+        for t in threads:
+            t.start()
+        # Drain while they ask, as the render thread would.
+        while any(t.is_alive() for t in threads):
+            controller._drain_control_commands()
+        for t in threads:
+            t.join()
+        controller._drain_control_commands()
+        assert len(seen) == threads_n * each
+        for n in range(threads_n):
+            mine = [int(m.split(':')[1]) for m in seen if m.startswith(f'{n}:')]
+            assert mine == list(range(each))
+
+    def test_a_full_queue_refuses(self, wired, caplog):
+        controller, manager = wired
+        controller.PLUGIN_ON_DEMAND_QUEUE_SIZE = 2
+        plugin = _plugin('p', manager)
+        assert plugin.request_on_demand()
+        assert plugin.request_on_demand()
+        assert plugin.request_on_demand() is None
+        assert 'queue full' in caplog.text
+        controller._poll_on_demand_requests()
+        assert controller._activate_on_demand.call_count == 2
+        assert plugin.request_on_demand()              # room again
+
+
+class TestStop:
+    def test_a_plugin_ends_its_own_session(self, wired):
+        controller, manager = wired
+        controller.on_demand_active = True
+        controller.on_demand_plugin_id = 'on-air'
+        controller._clear_on_demand = MagicMock()
+        assert _plugin('on-air', manager).end_on_demand()
+        controller._poll_on_demand_requests()
+        controller._clear_on_demand.assert_called_once_with(reason='requested-stop')
+        controller.cache_manager.delete.assert_not_called()
+
+    def test_a_plugin_cannot_end_another_plugins_session(self, wired):
+        controller, manager = wired
+        controller.on_demand_active = True
+        controller.on_demand_plugin_id = 'clock'       # the user started it
+        controller.on_demand_request_id = 'user'
+        controller._clear_on_demand = MagicMock()
+        _plugin('pomodoro-timer', manager).end_on_demand()
+        controller._poll_on_demand_requests()
+        controller._clear_on_demand.assert_not_called()
+        assert controller.on_demand_request_id == 'user'
+
+    def test_a_stop_with_no_session_does_nothing(self, wired):
+        controller, manager = wired
+        controller.on_demand_status = 'error'
+        controller._clear_on_demand = MagicMock()
+        _plugin('on-air', manager).end_on_demand()
+        controller._poll_on_demand_requests()
+        controller._clear_on_demand.assert_not_called()
+
+    def test_a_mailbox_stop_still_ends_any_session(self, wired):
+        controller, _ = wired
+        controller.on_demand_active = True
+        controller.on_demand_plugin_id = 'clock'
+        controller._clear_on_demand = MagicMock()
+        controller.mailbox['value'] = {'request_id': 's', 'action': 'stop',
+                                       'plugin_id': 'on-air'}
+        controller._poll_on_demand_requests()
+        controller._clear_on_demand.assert_called_once_with(reason='requested-stop')
+
+    def test_start_then_stop_from_one_thread_ends_the_session(self, wired):
+        controller, manager = wired
+
+        def activate(request):
+            controller.on_demand_active = True
+            controller.on_demand_plugin_id = request['plugin_id']
+
+        controller._activate_on_demand = MagicMock(side_effect=activate)
+        controller._clear_on_demand = MagicMock()
+        plugin = _plugin('pomodoro-timer', manager)
+        plugin.request_on_demand(mode='pomodoro', pinned=True)
+        plugin.end_on_demand()
+        controller._poll_on_demand_requests()
+        controller._activate_on_demand.assert_called_once()
+        controller._clear_on_demand.assert_called_once_with(reason='requested-stop')
+
+
+class TestNoDisplay:
+    """None is a plugin's cue to write the mailbox instead."""
+
+    def test_a_manager_with_no_handler_answers_none(self):
+        plugin = _plugin('p', _manager())
+        assert plugin.request_on_demand() is None
+        assert plugin.end_on_demand() is None
+
+    def test_no_plugin_manager_answers_none(self):
+        plugin = _plugin('p', None)
+        assert plugin.request_on_demand() is None
+        assert plugin.end_on_demand() is None
+
+    def test_an_old_cores_plugin_manager_answers_none(self):
+        class OldManager:
+            plugin_manifests = {}
+
+        plugin = _plugin('p', OldManager())
+        assert plugin.request_on_demand() is None
+        assert plugin.end_on_demand() is None
+
+    def test_a_handler_that_raises_answers_none(self):
+        def broken(request):
+            raise RuntimeError('boom')
+
+        plugin = _plugin('p', _manager(broken))
+        assert plugin.request_on_demand() is None
+        assert plugin.end_on_demand() is None
+
+    def test_a_handler_that_refuses_answers_none(self):
+        plugin = _plugin('p', _manager(lambda request: False))
+        assert plugin.request_on_demand() is None
+
+    def test_a_controller_built_without_init_refuses(self):
+        from src.display_controller import DisplayController
+        bare = DisplayController.__new__(DisplayController)
+        assert bare.submit_plugin_on_demand({'action': 'start'}) is False
+        assert bare._plugin_on_demand_pending() is False
+        bare._drain_plugin_on_demand()                 # nothing to do, no error
+
+    def test_the_feature_detection_pattern(self):
+        """The hasattr pattern from docs/PLUGIN_API_REFERENCE.md."""
+        writes = []
+
+        class OldCorePlugin:     # an older core's BasePlugin has no such method
+            pass
+
+        for plugin, expect_mailbox in ((OldCorePlugin(), True),
+                                       (_plugin('p', _manager()), True),
+                                       (_plugin('p', _manager(lambda r: True)), False)):
+            writes.clear()
+            if not (hasattr(plugin, 'request_on_demand')
+                    and plugin.request_on_demand(mode='m')):
+                writes.append('mailbox')
+            assert (writes == ['mailbox']) is expect_mailbox
+
+
+class TestArguments:
+    def test_the_manager_shapes_the_request(self):
+        got = []
+        plugin = _plugin('p', _manager(lambda r: got.append(r) or True))
+        plugin.request_on_demand()
+        plugin.end_on_demand()
+        start, stop = got
+        assert start['plugin_id'] == 'p' and start['mode'] is None
+        assert start['duration'] is None and start['pinned'] is False
+        assert start['source'] == 'plugin' and start['timestamp'] > 0
+        assert stop == {'action': 'stop', 'plugin_id': 'p', 'request_id': stop['request_id'],
+                        'timestamp': stop['timestamp'], 'source': 'plugin'}
+        assert start['request_id'] != stop['request_id']
+
+    @pytest.mark.parametrize('duration', [0, -5, float('inf'), float('nan')])
+    def test_no_positive_duration_means_no_limit(self, duration):
+        got = []
+        _plugin('p', _manager(lambda r: got.append(r) or True)).request_on_demand(
+            duration=duration)
+        assert got[0]['duration'] is None
+
+    @pytest.mark.parametrize('kwargs', [{'mode': 5}, {'mode': ''}, {'duration': '30'},
+                                        {'duration': True}])
+    def test_bad_arguments_raise(self, kwargs):
+        plugin = _plugin('p', _manager(lambda r: True))
+        with pytest.raises(ValueError):
+            plugin.request_on_demand(**kwargs)
+
+
+class TestMockManagers:
+    def test_a_magicmock_manager_reads_as_not_taken(self):
+        """A plugin's test with a MagicMock manager keeps its mailbox path."""
+        plugin = _plugin('p', MagicMock())
+        assert plugin.request_on_demand(mode='m') is None
+        assert plugin.end_on_demand() is None
+        plugin.plugin_manager.request_on_demand.assert_called_once_with(
+            'p', mode='m', duration=None, pinned=False)
+        plugin.plugin_manager.end_on_demand.assert_called_once_with('p')
+
+    def test_a_mocked_id_is_passed_through(self):
+        manager = MagicMock()
+        manager.request_on_demand.return_value = 'rid'
+        manager.end_on_demand.return_value = 'rid2'
+        plugin = _plugin('p', manager)
+        assert plugin.request_on_demand() == 'rid'
+        assert plugin.end_on_demand() == 'rid2'

test/test_plugin_runtime_snapshot.py

@@ -423,7 +423,7 @@ def web_listing(api_v3_module, api_v3_client, shared_cache, tmp_path):  # noqa:
         {"id": "clock", "name": "Clock", "version": "1.1.0"},
         {"id": "weather", "name": "Weather", "version": "3.0.0"},
     ])
-    api.plugin_store_manager.get_registry_info = MagicMock(return_value=None)
+    api.plugin_store_manager.get_cached_registry_info = MagicMock(return_value=None)
     api.plugin_store_manager._get_local_git_info = MagicMock(return_value=None)
     api.config_manager.load_config = MagicMock(return_value={
         "clock": {"enabled": True}, "weather": {"enabled": True}})

test/test_run_loop_golden.py

@@ -133,6 +133,32 @@ def scenario_on_demand_restored(h: RunLoopHarness):
     h.restore_on_demand("sports", mode="sports_upcoming", duration=40)
 
 
+def scenario_on_demand_named_live(h: RunLoopHarness):
+    # Games are on until t=70, but none involves a favourite, so
+    # has_live_content() (the live-priority answer) stays False throughout.
+    # A request naming sports_live still opens on it (it opened on
+    # sports_recent); asked for again after the games end, it has nothing to
+    # draw and the session moves on to the plugin's next mode.
+    h.add_plugin(FakePlugin("clock", ["clock"], duration=20))
+    h.add_plugin(FakePlugin(
+        "sports", ["sports_live", "sports_recent", "sports_upcoming"], duration=15,
+        live_priority=True,
+        content=lambda t, mode: mode != "sports_live" or t < 70))
+    h.on_demand_request(5, "n1", plugin_id="sports", mode="sports_live")
+    h.on_demand_request(40, "n2", action="stop")
+    h.on_demand_request(100, "n3", plugin_id="sports", mode="sports_live")
+    h.on_demand_request(140, "n4", action="stop")
+
+
+def scenario_on_demand_restore_failed(h: RunLoopHarness):
+    # A restart during a session whose plugin then fails to load: the
+    # session ends as an error before the first screen, and the rotation
+    # runs normally from the top.
+    h.add_plugin(FakePlugin("clock", ["clock"], duration=20))
+    h.add_plugin(FakePlugin("weather", ["weather"], duration=20))
+    h.restore_on_demand("gone", mode="gone", duration=40)
+
+
 def scenario_schedule(h: RunLoopHarness):
     # The clock starts at 22:59:30. Off from 23:01 until 23:05 (the window
     # spans midnight); dimmed from 23:00 until 23:01.
@@ -194,6 +220,8 @@ SCENARIOS = {
     "on_demand": (scenario_on_demand, 240),
     "on_demand_pinned": (scenario_on_demand_pinned, 160),
     "on_demand_restored": (scenario_on_demand_restored, 100),
+    "on_demand_named_live": (scenario_on_demand_named_live, 160),
+    "on_demand_restore_failed": (scenario_on_demand_restore_failed, 60),
     "schedule": (scenario_schedule, 400),
     "wifi_notice": (scenario_wifi_notice, 150),
     "follower": (scenario_follower, 80),

test/test_screen_runner.py

@@ -0,0 +1,455 @@
+"""ScreenRunner (src/screen_runner.py) on a scripted host and a fake clock.
+
+The golden traces (test_run_loop_golden.py) run it inside the real
+DisplayController; these pin down its own contract: which ExitReason each
+way of ending gives, the order it calls its host in, how the 125 Hz loop
+paces, and which service point asks what.
+"""
+
+from typing import Any, List, Optional, Tuple
+
+import pytest
+
+from src.display_arbiter import (
+    RELOAD_PLAN, SCREEN_PREEMPTERS, FramePolicy, ScreenPlan, Source,
+)
+from src.screen_runner import (
+    AFTER_COMPLETED_LOOP, AFTER_LOOP, DYNAMIC_GRACE, FINAL, FRAME, HIGH_FPS_INTERVAL,
+    Checkpoint, ExitReason, FirstFrame, NoticeRead, Screen, ScreenRunner,
+)
+
+WIFI_PLAN = ScreenPlan(Source.WIFI)
+
+
+class Clock:
+    """time/perf_counter read ``now``; sleep advances it."""
+
+    def __init__(self):
+        self.now = 0.0
+        self.sleeps: List[float] = []
+
+    def time(self) -> float:
+        return self.now
+
+    def perf_counter(self) -> float:
+        return self.now
+
+    def sleep(self, seconds: float) -> None:
+        self.sleeps.append(round(seconds, 6))
+        self.now += seconds
+
+
+class Host:
+    """A ScreenHost whose answers are scripted; records every call."""
+
+    def __init__(self, clock: Clock, *, shown=True, raised=False, minimum=10.0,
+                 maximum=10.0, dynamic=False, policy=FramePolicy.STATIC,
+                 completed=True, draws=None, checks=None, work=0.0,
+                 cycle_complete_at=None, dwell_to=None):
+        self.clock = clock
+        self.calls: List[Tuple[Any, ...]] = []
+        self.shown, self.raised = shown, raised
+        self.minimum, self.maximum = minimum, maximum
+        self.dynamic, self.policy, self.completed = dynamic, policy, completed
+        #: display() results for the frames after the first, in order.
+        self.draws = list(draws or [])
+        #: (checkpoint name, frame number) -> plan, or a callable(screen, cp).
+        self.checks = checks or {}
+        self.work = work
+        self.cycle_complete_at = cycle_complete_at
+        self.dwell_to = dwell_to
+        self.frames = 0
+
+    def first_frame(self, plan, plugin):
+        self.calls.append(("first", plan.mode))
+        return FirstFrame(self.shown, self.raised, False)
+
+    def complete_plan(self, plan, plugin):
+        self.calls.append(("complete",))
+        if not self.completed:
+            return None
+        return ScreenPlan(plan.source, mode=plan.mode, min_duration=self.minimum,
+                          max_duration=self.maximum, dynamic=self.dynamic,
+                          frame_policy=self.policy, preemptible_by=plan.preemptible_by)
+
+    def draw(self, screen):
+        self.frames += 1
+        self.calls.append(("draw", self.frames))
+        self.clock.now += self.work
+        return self.draws.pop(0) if self.draws else True
+
+    def after_frame(self, screen):
+        self.calls.append(("after_frame",))
+
+    def tick(self):
+        self.calls.append(("tick",))
+
+    def service(self, screen):
+        self.calls.append(("service",))
+        return ("scan", self.frames)
+
+    def wait_frame(self, interval, screen):
+        self.calls.append(("wait", interval))
+        self.clock.sleep(interval)
+        return self._scripted("wait", screen)
+
+    def check(self, screen, checkpoint, live_scan=None):
+        self.calls.append(("check", checkpoint.name, live_scan))
+        return self._scripted(checkpoint.name, screen, checkpoint)
+
+    def _scripted(self, name, screen, checkpoint=None):
+        answer = self.checks.get((name, self.frames))
+        if callable(answer):
+            return answer(screen, checkpoint)
+        return answer
+
+    def dwell(self, seconds):
+        self.calls.append(("dwell", round(seconds, 6)))
+        self.clock.now = self.dwell_to if self.dwell_to is not None else self.clock.now + seconds
+
+    def cycle_complete(self, screen):
+        self.calls.append(("cycle?",))
+        return self.cycle_complete_at is not None and self.clock.now >= self.cycle_complete_at
+
+
+PLAN = ScreenPlan(Source.ROTATION, mode="clock", preemptible_by=SCREEN_PREEMPTERS)
+
+
+def _run(**kwargs) -> Tuple[Any, Host, Clock]:
+    clock = Clock()
+    host = Host(clock, **kwargs)
+    outcome = ScreenRunner(clock, host).run(PLAN, plugin=object())
+    return outcome, host, clock
+
+
+def _names(host, *kinds):
+    return [c for c in host.calls if c[0] in kinds]
+
+
+class TestFirstFrame:
+
+    def test_no_plugin_is_empty_without_a_dispatch(self):
+        clock = Clock()
+        host = Host(clock)
+        outcome = ScreenRunner(clock, host).run(PLAN, plugin=None)
+        assert outcome.exit_reason is ExitReason.EMPTY
+        assert host.calls == []
+
+    @pytest.mark.parametrize("raised,reason", [(False, ExitReason.EMPTY),
+                                               (True, ExitReason.ERROR)])
+    def test_nothing_shown(self, raised, reason):
+        outcome, host, _ = _run(shown=False, raised=raised)
+        assert outcome.exit_reason is reason
+        assert host.calls == [("first", "clock")]
+
+    def test_an_on_demand_session_with_no_time_left(self):
+        outcome, host, _ = _run(completed=False)
+        assert outcome.exit_reason is ExitReason.PREEMPTED
+        assert outcome.preempted_by is None
+        assert host.calls == [("first", "clock"), ("complete",)]
+
+
+class TestStaticLoop:
+
+    def test_runs_its_duration_one_frame_a_second(self):
+        outcome, host, clock = _run(maximum=5.0)
+        assert outcome.exit_reason is ExitReason.DURATION
+        assert outcome.elapsed == 5.0
+        # Frames at 1..4 s; the wait that reaches 5 s ends it before a fifth.
+        assert host.frames == 4
+        assert clock.sleeps == [1.0] * 5
+        # Each frame: wait, tick, draw, follower frame, service, the check.
+        assert host.calls[2:9] == [("wait", 1.0), ("tick",), ("draw", 1), ("after_frame",),
+                                   ("service",), ("check", "frame", ("scan", 1)), ("wait", 1.0)]
+        # A completed loop: the after-loop look reads no notice, then FINAL.
+        assert host.calls[-2:] == [("check", "after-completed-loop", None), ("check", "final", None)]
+
+    def test_preempted_between_frames(self):
+        by = ScreenPlan(Source.ON_DEMAND, mode="x")
+        outcome, host, _ = _run(maximum=30.0, checks={("frame", 3): by})
+        assert outcome.exit_reason is ExitReason.PREEMPTED
+        assert outcome.preempted_by is by
+        assert outcome.elapsed == 3.0
+        # Decided at the service point: no second look, no dwell.
+        assert host.calls[-1] == ("check", "frame", ("scan", 3))
+
+    def test_preempted_by_a_socket_command_in_the_frame_wait(self):
+        outcome, host, _ = _run(maximum=30.0, checks={("wait", 2): WIFI_PLAN})
+        assert outcome.exit_reason is ExitReason.PREEMPTED
+        assert host.calls[-1] == ("wait", 1.0)
+
+    def test_display_false_makes_up_the_minimum(self):
+        outcome, host, _ = _run(maximum=12.0, draws=[True, False])
+        assert outcome.exit_reason is ExitReason.DISPLAY_FALSE
+        # The loop ended early: the after-loop look may read a notice, then
+        # the dwell makes up the rest of the 12 s.
+        assert _names(host, "check", "dwell")[-4:] == [
+            ("check", "after-loop", None), ("dwell", 10.0),
+            ("check", "after-dwell", None), ("check", "final", None)]
+        assert outcome.elapsed == 12.0
+
+    def test_a_notice_that_cuts_the_dwell_short_ends_the_screen(self):
+        def notice(screen, checkpoint):
+            assert checkpoint.notice is NoticeRead.ALWAYS
+            return WIFI_PLAN if checkpoint.notice_counts else None
+        outcome, _, _ = _run(maximum=12.0, draws=[False], dwell_to=6.0,
+                             checks={("after-dwell", 1): notice})
+        assert outcome.exit_reason is ExitReason.PREEMPTED
+
+    def test_a_notice_after_a_full_dwell_does_not(self):
+        def notice(screen, checkpoint):
+            return WIFI_PLAN if checkpoint.notice_counts else None
+        outcome, _, _ = _run(maximum=12.0, draws=[False],
+                             checks={("after-dwell", 1): notice})
+        assert outcome.exit_reason is ExitReason.DISPLAY_FALSE
+
+    def test_a_reload_ends_the_loop_but_the_screen_counts(self):
+        outcome, host, _ = _run(maximum=30.0, checks={("frame", 2): RELOAD_PLAN})
+        assert outcome.exit_reason is ExitReason.RELOAD
+        # Not decided at the service point: the after-loop look, the dwell
+        # (which returns at once while a reload waits) and FINAL follow.
+        assert ("check", "after-loop", None) in host.calls
+        assert ("check", "final", None) in host.calls
+
+    def test_a_change_after_the_loop_preempts(self):
+        by = ScreenPlan(Source.ROTATION, mode="weather")
+        outcome, _, _ = _run(maximum=3.0, checks={("final", 2): by})
+        assert outcome.exit_reason is ExitReason.PREEMPTED
+        assert outcome.preempted_by is by
+
+    def test_a_dynamic_screen_keeps_going_on_false(self):
+        outcome, host, _ = _run(minimum=3.0, maximum=8.0, dynamic=True,
+                                draws=[False, False, False])
+        assert outcome.exit_reason is ExitReason.DURATION
+        assert host.frames == 7
+
+
+class TestHighFpsLoop:
+
+    def test_paces_to_the_deadline(self):
+        outcome, host, clock = _run(maximum=0.05, policy=FramePolicy.HIGH_FPS, work=0.003)
+        assert outcome.exit_reason is ExitReason.DURATION
+        # 3 ms of drawing leaves 5 ms of an 8 ms frame to sleep.
+        assert set(clock.sleeps) == {round(HIGH_FPS_INTERVAL - 0.003, 6)}
+
+    def test_an_overrun_frame_still_yields(self):
+        _, _, clock = _run(maximum=0.05, policy=FramePolicy.HIGH_FPS, work=0.02)
+        assert set(clock.sleeps) == {0.001}
+
+    def test_service_before_the_sleep_check_after(self):
+        _, host, clock = _run(maximum=0.016, policy=FramePolicy.HIGH_FPS)
+        first = host.calls[2:7]
+        assert first == [("draw", 1), ("after_frame",), ("tick",), ("service",),
+                         ("check", "frame", ("scan", 1))]
+        assert clock.sleeps[0] == HIGH_FPS_INTERVAL
+
+    def test_preempted_after_the_frames_sleep(self):
+        outcome, _, clock = _run(maximum=30.0, policy=FramePolicy.HIGH_FPS,
+                                 checks={("frame", 3): WIFI_PLAN})
+        assert outcome.exit_reason is ExitReason.PREEMPTED
+        assert clock.now == pytest.approx(3 * HIGH_FPS_INTERVAL)
+
+    def test_display_false_has_no_make_up_dwell(self):
+        outcome, host, _ = _run(maximum=30.0, policy=FramePolicy.HIGH_FPS,
+                                draws=[True, False])
+        assert outcome.exit_reason is ExitReason.DISPLAY_FALSE
+        assert not _names(host, "dwell")
+
+
+class TestDynamicDuration:
+
+    def test_cycle_complete_after_the_minimum_and_grace(self):
+        outcome, host, _ = _run(minimum=3.0, maximum=20.0, dynamic=True,
+                                cycle_complete_at=1.0)
+        assert outcome.exit_reason is ExitReason.CYCLE_COMPLETE
+        # Not asked before minimum + grace (3.5 s): the 1 Hz loop's first
+        # frame at or past it is the one at 4 s.
+        assert outcome.elapsed == 4.0
+        assert DYNAMIC_GRACE == 0.5
+
+    def test_capped_at_the_maximum(self):
+        outcome, host, _ = _run(minimum=3.0, maximum=6.0, dynamic=True)
+        assert outcome.exit_reason is ExitReason.DURATION
+        # The end-of-screen log asks the plugin once more, before FINAL.
+        assert host.calls[-3:] == [("check", "after-completed-loop", None), ("cycle?",),
+                                   ("check", "final", None)]
+
+    def test_high_fps_cycle_complete(self):
+        outcome, _, _ = _run(minimum=0.02, maximum=1.0, dynamic=True,
+                             policy=FramePolicy.HIGH_FPS, cycle_complete_at=0.0)
+        assert outcome.exit_reason is ExitReason.CYCLE_COMPLETE
+        assert outcome.elapsed >= 0.02 + DYNAMIC_GRACE
+
+
+class TestCheckpoints:
+
+    @pytest.mark.parametrize("checkpoint,notice,reload", [
+        (FRAME, NoticeRead.IF_UNDECIDED, True),
+        (AFTER_LOOP, NoticeRead.IF_UNDECIDED, False),
+        (AFTER_COMPLETED_LOOP, NoticeRead.NEVER, False),
+        (FINAL, NoticeRead.NEVER, False),
+    ])
+    def test_what_each_service_point_considers(self, checkpoint, notice, reload):
+        """A reload counts only between frames; the notice file is read
+        where the loop read it before stage 3."""
+        assert isinstance(checkpoint, Checkpoint)
+        assert (checkpoint.notice, checkpoint.reload) == (notice, reload)
+
+    def test_the_screen_carries_the_completed_plan(self):
+        seen: List[Optional[Screen]] = []
+
+        def grab(screen, checkpoint):
+            seen.append(screen)
+        _run(maximum=2.0, checks={("frame", 1): grab})
+        assert seen[0].plan.frame_policy is FramePolicy.STATIC
+        assert seen[0].mode == "clock"
+
+
+class TestControllerServicePoint:
+    """DisplayController._screen_check: the reads it makes and what it claims,
+    on a controller built by the run-loop harness."""
+
+    @pytest.fixture
+    def dc(self, tmp_path):
+        import os
+        os.environ.setdefault("EMULATOR", "true")
+        from test._run_loop_harness import FakePlugin, RunLoopHarness
+        h = RunLoopHarness(tmp_path, horizon=10)
+        h.add_plugin(FakePlugin("clock", ["clock"], duration=20))
+        h.add_plugin(FakePlugin("sports", ["sports_live"], duration=20,
+                                live=(0, 100), live_priority=True))
+        dc = h.controller
+        dc.current_display_mode = "clock"
+        dc.current_mode_index = 0
+        dc.reads = []
+
+        def read():
+            dc.reads.append(1)
+            return {"message": "AP mode", "expires_at": 1e12}
+        dc._check_wifi_status_message = read
+        return dc
+
+    @staticmethod
+    def _screen(mode="clock"):
+        from src.display_arbiter import ArbiterState, rotation_plan
+        return Screen(rotation_plan(ArbiterState(current_mode=mode)), plugin=None,
+                      accepts_display_mode=False, start=0.0)
+
+    def test_a_pending_notice_is_read_and_ends_the_screen(self, dc):
+        by = dc._screen_check(self._screen(), FRAME)
+        assert by.source is Source.WIFI and len(dc.reads) == 1
+
+    def test_not_read_once_the_mode_has_moved(self, dc):
+        dc.current_display_mode = "sports_live"
+        by = dc._screen_check(self._screen(), FRAME)
+        assert by.source is Source.ROTATION and dc.reads == []
+
+    def test_not_read_while_scheduled_off(self, dc):
+        dc.is_display_active = False
+        by = dc._screen_check(self._screen(), FRAME)
+        assert by.source is Source.SCHEDULED_OFF and dc.reads == []
+
+    def test_not_read_during_on_demand(self, dc):
+        dc.on_demand_active = True
+        dc.on_demand_schedule_override = True
+        assert dc._screen_check(self._screen(), FRAME) is None
+        assert dc.reads == []
+
+    def test_a_live_takeover_is_claimed_before_the_notice(self, dc):
+        by = dc._screen_check(self._screen(), FRAME, live_scan=("sports_live",))
+        assert by.source is Source.LIVE and dc.reads == []
+        assert dc.current_display_mode == "sports_live"
+        assert dc._live_takeover_unshown is True and dc._live_resume_index == 0
+
+    def test_after_a_completed_loop_the_notice_is_not_read(self, dc):
+        assert dc._screen_check(self._screen(), AFTER_COMPLETED_LOOP) is None
+        assert dc.reads == []
+
+    def test_after_a_full_dwell_it_is_read_but_does_not_count(self, dc):
+        from src.screen_runner import after_dwell
+        assert dc._screen_check(self._screen(), after_dwell(False)) is None
+        assert len(dc.reads) == 1
+
+    def test_a_reload_counts_only_between_frames(self, dc):
+        dc._check_wifi_status_message = lambda: None
+        dc._pending_plugin_reloads = ("pending",)
+        assert dc._screen_check(self._screen(), FRAME) is RELOAD_PLAN
+        assert dc._screen_check(self._screen(), AFTER_LOOP) is None
+
+    def test_an_on_demand_index_past_a_shortened_list_starts_again(self, dc):
+        """_take_plan writes the shown index back, so the session's next
+        step goes on from the mode actually shown."""
+        from src.display_arbiter import Arbiter, ArbiterInputs
+        dc.on_demand_active = True
+        dc.on_demand_modes = ["clock", "sports_live"]
+        dc.on_demand_mode_index = 5            # the list shrank under it
+        inputs = ArbiterInputs(schedule_on=True, on_demand_active=True,
+                               follower_active=False)
+        plan = dc._take_plan(Arbiter.decide(dc._arbiter_state(), inputs, 0.0))
+        assert plan.mode == "clock" and dc.on_demand_mode_index == 0
+        dc._advance_on_demand()
+        assert dc.current_display_mode == "sports_live"
+
+
+@pytest.mark.parametrize("policy,report_hold", [(FramePolicy.HIGH_FPS, True),
+                                                (FramePolicy.STATIC, False)])
+def test_only_the_high_fps_loop_reports_a_held_frame(policy, report_hold):
+    """#758's report_hold: the 125 Hz loop times frames held by update();
+    the 1 Hz loop's frames are a second apart and must not."""
+    from unittest.mock import MagicMock
+    from src.display_controller import _ScreenHost
+    controller = MagicMock()
+    plan = ScreenPlan(Source.ROTATION, mode="ticker", frame_policy=policy)
+    plugin = object()
+    _ScreenHost(controller).draw(Screen(plan, plugin, True, 0.0))
+    controller._display_once.assert_called_once_with(plugin, "ticker", True,
+                                                     report_hold=report_hold)
+
+
+def _rows(tmp_path, horizon, build):
+    import os
+    os.environ.setdefault("EMULATOR", "true")
+    from test._run_loop_harness import RunLoopHarness
+    h = RunLoopHarness(tmp_path, horizon=horizon)
+    build(h)
+    return h.run()["screens"]
+
+
+class TestThroughRun:
+    """Service points that only the full loop reaches, on the harness."""
+
+    def test_a_notice_pending_when_a_later_frame_is_empty_ends_the_screen(self, tmp_path):
+        """The after-loop look reads the notice when the loop ended early: a
+        1 Hz screen whose second frame has nothing to show must not sit in
+        its make-up dwell (which only notices a notice that arrives during
+        it) while the notice expires."""
+        from test._run_loop_harness import FakePlugin
+
+        def build(h):
+            h.add_plugin(FakePlugin("flaky", ["flaky"], duration=12, first_frame_only=True))
+            h.add_plugin(FakePlugin("clock", ["clock"], duration=12))
+            h.wifi_message(0.5, "Connected to HomeNet", duration=5)
+        rows = _rows(tmp_path, 30, build)
+        assert rows[0][1] == "flaky" and rows[0][2] == 1.0
+        assert rows[1][1] == "<wifi>"
+        # ... and the mode it cut short comes back, not the next one.
+        after = next(row for row in rows[1:] if row[1] != "<wifi>")
+        assert after[1] == "flaky"
+
+    def test_vegas_yielding_to_a_follower_shows_a_rotation_screen_first(self, tmp_path):
+        """Pins today's behaviour (docs/RUN_LOOP_REDESIGN.md, "may be
+        wrong"): the interrupt check stops the ticker for a follower, but
+        the yield path never looks at one, so a rotation screen runs its
+        full duration before the next pass hands the panel to the leader."""
+        from test._run_loop_harness import FakePlugin
+
+        def build(h):
+            h.add_plugin(FakePlugin("clock", ["clock"], duration=20))
+            h.add_plugin(FakePlugin("weather", ["weather"], duration=20))
+            h.enable_vegas(cycle=30)
+            h.sync.follower_windows = [(10, 60)]
+        rows = _rows(tmp_path, 50, build)
+        assert rows[0][1] == "<vegas>" and rows[0][3] == "vegas-interrupt"
+        assert 10.0 <= rows[0][0] + rows[0][2] <= 10.2
+        assert rows[1][1] == "clock" and rows[1][2] == 20.0
+        assert rows[2][1] == "<follower>"

test/test_snapshot_owed_frame.py

@@ -0,0 +1,183 @@
+"""A frame the preview throttle skipped still reaches the snapshot.
+
+The preview snapshot (/api/v3/display/current, the web UI's live preview) is
+only written from update_display(), at most once per write interval. A screen
+that draws its card once and then holds it -- soccer's recent/upcoming cards
+skip redundant redraws -- pushes exactly one frame. When that push lands inside
+the interval, e.g. a few milliseconds after the on-demand start's clear wrote a
+black frame, the throttle skips it and nothing ever writes it: on ledpi the
+preview stayed black for soccer's whole 15 s screen while the panel showed the
+card, and the next screen "rendered immediately".
+
+Runs the real DisplayManager on the emulator, like test_display_dirty_tracking.
+"""
+
+import os
+import sys
+import types
+
+os.environ["EMULATOR"] = "true"
+
+import pytest
+from PIL import Image
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
+
+
+@pytest.fixture(scope="module")
+def dm(tmp_path_factory):
+    from src.display_manager import DisplayManager
+    DisplayManager._instance = None
+    manager = DisplayManager({
+        "display": {
+            "hardware": {"rows": 32, "cols": 64, "chain_length": 2,
+                         "parallel": 1, "brightness": 90},
+            "runtime": {"gpio_slowdown": 0},
+        },
+    }, suppress_test_pattern=True)
+    manager._snapshot_path = str(
+        tmp_path_factory.mktemp("owed_snapshot") / "led_matrix_preview.png")
+    yield manager
+    DisplayManager._instance = None
+
+
+@pytest.fixture
+def viewer(dm, monkeypatch, tmp_path):
+    """A preview is open (1 s write interval); fresh snapshot bookkeeping."""
+    monkeypatch.setattr(dm, "_viewer_is_fresh", lambda now: True)
+    dm._viewer_was_fresh = True
+    dm._snapshot_path = str(tmp_path / "snap.png")
+    dm._last_snapshot_ts = 0.0
+    dm._last_snapshot_touch_ts = 0.0
+    dm._last_snapshot_digest = None
+    dm._saved_snapshot_digest = None
+    dm._snapshot_owed = False
+    dm.set_scrolling_state(False)
+    return dm
+
+
+def _lit(path):
+    with Image.open(path) as img:
+        return sum(1 for p in img.convert("RGB").getdata() if max(p) > 20)
+
+
+def _age_last_write(dm, seconds=2.0):
+    """As if `seconds` had passed since the last snapshot write."""
+    dm._last_snapshot_ts -= seconds
+    dm._last_snapshot_touch_ts -= seconds
+
+
+def _clear_then_draw_card(dm):
+    """The on-demand start's clear, then the card a few ms later."""
+    dm.clear()
+    dm.update_display()                       # black frame: written
+    assert _lit(dm._snapshot_path) == 0
+    dm.draw.rectangle([4, 4, 40, 20], fill=(255, 255, 0))
+    dm.update_display()                       # the card: inside the interval
+
+
+def _controller(dm):
+    from src import display_controller as dc_module
+    controller = dc_module.DisplayController.__new__(dc_module.DisplayController)
+    controller.plugin_manager = None
+    controller.display_manager = dm
+    return controller
+
+
+class _HoldingPlugin:
+    """Already showing its card: display() returns True and draws nothing."""
+
+    plugin_id = "holding"
+
+    def __init__(self):
+        self.calls = 0
+
+    def display(self, display_mode=None, force_clear=False):
+        self.calls += 1
+        return True
+
+
+def test_a_held_card_reaches_the_preview_on_the_next_frame(viewer):
+    dm = viewer
+    _clear_then_draw_card(dm)
+    assert _lit(dm._snapshot_path) == 0       # the throttle skipped the card
+
+    controller = _controller(dm)
+    plugin = _HoldingPlugin()
+    _age_last_write(dm)
+    # The render loop's next frame: the plugin draws nothing and makes no
+    # update_display() call, as soccer's switch cards do.
+    assert controller._display_once(plugin, "soccer_eng.1_recent", True) is True
+    assert plugin.calls == 1
+    assert _lit(dm._snapshot_path) > 0
+
+
+def test_the_owed_write_still_waits_out_the_interval(viewer, monkeypatch):
+    dm = viewer
+    _clear_then_draw_card(dm)
+    saves = []
+    monkeypatch.setattr(dm, "_save_snapshot", lambda image: saves.append(image))
+    dm.write_owed_snapshot()                  # still inside the interval
+    assert saves == []
+    _age_last_write(dm)
+    dm.write_owed_snapshot()
+    assert len(saves) == 1
+    # Written: nothing is owed, so later frames do no work and the unchanged
+    # frame is not encoded again.
+    assert dm._snapshot_owed is False
+    _age_last_write(dm)
+    dm.write_owed_snapshot()
+    assert len(saves) == 1
+
+
+def test_a_failed_owed_write_stays_owed_and_is_retried(viewer, monkeypatch):
+    dm = viewer
+    _clear_then_draw_card(dm)
+    _age_last_write(dm)
+    attempts = []
+
+    def failing_save(image):
+        attempts.append(image)
+        raise OSError("disk full")
+
+    monkeypatch.setattr(dm, "_save_snapshot", failing_save)
+    dm.write_owed_snapshot()                  # the write fails
+    assert len(attempts) == 1
+    assert dm._snapshot_owed is True          # still owed: a held screen
+    saves = []                                # makes no update_display()
+    monkeypatch.setattr(dm, "_save_snapshot", lambda image: saves.append(image))
+    dm.write_owed_snapshot()                  # retried on the next frame
+    assert len(saves) == 1
+    assert dm._snapshot_owed is False
+
+
+def test_nothing_owed_after_a_frame_that_was_written(viewer, monkeypatch):
+    dm = viewer
+    dm.draw.rectangle([0, 0, 8, 8], fill=(0, 255, 0))
+    dm.update_display()                       # due: written at once
+    assert dm._snapshot_owed is False
+    calls = []
+    monkeypatch.setattr(dm, "_write_snapshot_if_due",
+                        lambda *a, **k: calls.append(a))
+    dm.write_owed_snapshot()
+    assert calls == []
+
+
+def test_an_unchanged_frame_inside_the_interval_is_not_owed(viewer):
+    dm = viewer
+    dm.draw.rectangle([0, 0, 8, 8], fill=(0, 0, 255))
+    dm.update_display()
+    dm.update_display()                       # same frame, inside the interval
+    assert dm._snapshot_owed is False
+
+
+def test_a_controller_without_the_hook_still_draws():
+    """Controllers built without a display manager (tests) are unaffected."""
+    from src import display_controller as dc_module
+    controller = dc_module.DisplayController.__new__(dc_module.DisplayController)
+    controller.plugin_manager = None
+    plugin = _HoldingPlugin()
+    assert controller._display_once(plugin, "x", True) is True
+    controller.display_manager = types.SimpleNamespace()
+    assert controller._display_once(plugin, "x", True) is True
+    assert plugin.calls == 2

test/test_sports_favorites.py

@@ -0,0 +1,280 @@
+"""src.common.sports_favorites: behaviour, the _favorite_key seam, host contract.
+
+The cases follow ledmatrix-plugins' ``scripts/test_favourite_matching.py``
+(the tables the family 6 reconcile was checked against), with the favourites
+given as each plugin's resolver hands them over: as typed for the
+abbreviation sports, as ESPN team ids for an NRL-style host that overrides
+``_favorite_key``.
+"""
+
+import ast
+import logging
+from datetime import datetime, timedelta, timezone
+from pathlib import Path
+
+import pytest
+
+from src.common import sports_favorites
+from src.common.sports_favorites import (
+    SportsFavoritesMixin,
+    SportsRecentFavoritesMixin,
+    SportsUpcomingFavoritesMixin,
+)
+from src.common.sports_helpers import SportsHelpersMixin
+
+LOG = logging.getLogger("test_sports_favorites")
+
+
+def _id_key(self, game, side):
+    """NRL's override: the ESPN team id, None when it is missing."""
+    team_id = game.get(f"{side}_id")
+    return None if team_id is None else str(team_id)
+
+
+def host(favorites, by_id=False, limit=3):
+    """A manager stand-in: the three mixins over SportsHelpersMixin's default key."""
+    attrs = {"_favorite_key": _id_key} if by_id else {}
+    cls = type("Host", (SportsUpcomingFavoritesMixin, SportsRecentFavoritesMixin,
+                        SportsFavoritesMixin, SportsHelpersMixin), attrs)
+    h = cls()
+    h.logger = LOG
+    h.favorite_teams = favorites
+    h.upcoming_games_to_show = h.recent_games_to_show = limit
+    return h
+
+
+TEAM = {"1": "AAA", "2": "BBB", "3": "CCC", "4": "DDD", "41": "NEW", "42": "NEW"}
+
+
+def match(home, away, **extra):
+    g = {"home_id": home, "home_abbr": TEAM[home], "away_id": away, "away_abbr": TEAM[away]}
+    g.update(extra)
+    return g
+
+
+GAMES = {
+    "AAA home v BBB": match("1", "2"),
+    "BBB home v AAA": match("2", "1"),
+    "CCC v DDD": match("3", "4"),
+    "Knights (NEW 41) v CCC": match("41", "3"),
+    "Warriors (NEW 42) v CCC": match("42", "3"),
+    "AAA v BBB, no ids": {"home_abbr": "AAA", "away_abbr": "BBB"},
+    "ids 1 v 2, no abbrs": {"home_id": "1", "away_id": "2"},
+    "AAA v BBB, int ids": match("1", "2", home_id=1, away_id=2),
+    "lower-case abbrs": {"home_abbr": "aaa ", "away_abbr": "bbb"},
+    "empty game": {},
+}
+
+#: label -> favorite_teams as the resolver hands it over.
+FAVORITES = {
+    "none": [],
+    "AAA": ["AAA"],
+    "aaa": ["aaa"],
+    "' AAA '": [" AAA "],
+    "1": ["1"],
+    "int 1": [1],
+    "AAA,CCC": ["AAA", "CCC"],
+    "NEW": ["NEW"],
+    "41": ["41"],
+    "'None'": ["None"],
+    "blank": ["", "  "],
+}
+
+#: (favourites, game) -> answer with the abbreviation key, then the id key.
+EXPECTED_IS_FAVORITE = {
+    "AAA home v BBB": {"AAA": "Y.", "aaa": "Y.", "' AAA '": "Y.", "1": ".Y", "int 1": ".Y",
+                       "AAA,CCC": "Y."},
+    "BBB home v AAA": {"AAA": "Y.", "aaa": "Y.", "' AAA '": "Y.", "1": ".Y", "int 1": ".Y",
+                       "AAA,CCC": "Y."},
+    "CCC v DDD": {"AAA,CCC": "Y."},
+    "Knights (NEW 41) v CCC": {"AAA,CCC": "Y.", "NEW": "Y.", "41": ".Y"},
+    "Warriors (NEW 42) v CCC": {"AAA,CCC": "Y.", "NEW": "Y."},
+    "AAA v BBB, no ids": {"AAA": "Y.", "aaa": "Y.", "' AAA '": "Y.", "AAA,CCC": "Y."},
+    "ids 1 v 2, no abbrs": {"1": ".Y", "int 1": ".Y"},
+    "AAA v BBB, int ids": {"AAA": "Y.", "aaa": "Y.", "' AAA '": "Y.", "1": ".Y",
+                           "int 1": ".Y", "AAA,CCC": "Y."},
+    "lower-case abbrs": {"AAA": "Y.", "aaa": "Y.", "' AAA '": "Y.", "AAA,CCC": "Y."},
+    "empty game": {},
+}
+
+
+@pytest.mark.parametrize("game_label", sorted(GAMES))
+@pytest.mark.parametrize("fav_label", sorted(FAVORITES))
+def test_is_favorite_game(fav_label, game_label):
+    want = EXPECTED_IS_FAVORITE[game_label].get(fav_label, "..")
+    got = "".join("Y" if host(FAVORITES[fav_label], by_id)._is_favorite_game(dict(GAMES[game_label]))
+                  else "." for by_id in (False, True))
+    assert got == want
+
+
+class TestFavoriteCode:
+    @pytest.mark.parametrize("value, code", [
+        ("bos", "BOS"), (" BOS ", "BOS"), ("BOS", "BOS"), (41, "41"),
+        ("", None), ("   ", None), (None, None),
+    ])
+    def test_normalises(self, value, code):
+        assert SportsFavoritesMixin._favorite_code(value) == code
+
+    def test_a_missing_id_is_not_the_string_none(self):
+        """str(None) would match a favourite typed "None"; None matches nothing."""
+        h = host(["None"], by_id=True)
+        assert h._is_favorite_game({"home_abbr": "AAA", "away_abbr": "BBB"}) is False
+        assert h._is_favorite_game({}) is False
+
+    def test_a_none_favorites_list_matches_nothing(self):
+        assert host(None)._is_favorite_game(dict(GAMES["AAA home v BBB"])) is False
+
+
+# ---------------------------------------------------------------------------
+# Selection. A shuffled slate: two games share id s2, two have no id, s9 has
+# no start time. Hours from now; Recent gets the same slate in the past.
+# ---------------------------------------------------------------------------
+
+NOW = datetime(2026, 10, 5, 15, tzinfo=timezone.utc)
+SLATE = (("s5", "41", "2", 5), ("s1", "1", "2", 1), ("s3", "4", "3", 3),
+         ("s2", "3", "1", 2), ("s7", "2", "3", 7), ("s4", "1", "4", 4),
+         ("s6", "42", "4", 6), ("s2", "1", "4", 8), ("s9", "1", "3", None),
+         (None, "3", "1", 9), (None, "2", "1", 10))
+
+
+def slate(recent):
+    sign = -1 if recent else 1
+    games = []
+    for gid, home, away, hours in SLATE:
+        g = match(home, away, id=gid)
+        if hours is not None:
+            g["start_time_utc"] = NOW + timedelta(hours=sign * hours)
+        games.append(g)
+    return games
+
+
+def pick(favorites, limit, recent, by_id=False):
+    h = host(favorites, by_id, limit)
+    method = h._select_recent_games_for_display if recent else h._select_games_for_display
+    return ",".join(g["id"] or "~" for g in method(slate(recent), favorites)) or "none"
+
+
+ALL = "s1,s2,s3,s4,s5,s6,s7,s2,~,~,s9"
+
+#: (favourites, per-team limit) -> picked ids, the same for Upcoming and Recent.
+EXPECTED_SELECT = {
+    (("AAA",), 1): "s1", (("AAA",), 2): "s1,s2", (("AAA",), 5): "s1,s2,s4,~,~",
+    (("aaa",), 5): "s1,s2,s4,~,~", ((" AAA ",), 2): "s1,s2",
+    (("AAA", "CCC"), 1): "s1,s2", (("AAA", "CCC"), 2): "s1,s2,s3",
+    (("AAA", "CCC"), 5): "s1,s2,s3,s4,s7,~,~,s9",
+    (("AAA", "ZZZ"), 2): "s1,s2", (("NEW",), 2): "s5,s6",
+    (("ZZZ",), 2): "none", ((), 1): ALL,
+}
+
+
+@pytest.mark.parametrize("recent", [False, True], ids=["upcoming", "recent"])
+@pytest.mark.parametrize("favorites, limit", sorted(EXPECTED_SELECT))
+def test_select(favorites, limit, recent):
+    assert pick(list(favorites), limit, recent) == EXPECTED_SELECT[(favorites, limit)]
+
+
+class TestSelectByTeamId:
+    """The NRL-style host: the key is the team id, so NEW is two teams."""
+
+    @pytest.mark.parametrize("recent", [False, True])
+    def test_one_club_of_a_shared_abbreviation(self, recent):
+        assert pick(["41"], 2, recent, by_id=True) == "s5"
+
+    @pytest.mark.parametrize("recent", [False, True])
+    def test_an_unresolved_abbreviation_matches_nothing(self, recent):
+        assert pick(["NEW"], 2, recent, by_id=True) == "none"
+
+    def test_ids_select_like_abbreviations(self):
+        assert pick(["1"], 5, False, by_id=True) == "s1,s2,s4,~,~"
+
+
+class TestSelectionRules:
+    def test_a_game_between_two_favourites_counts_for_both(self):
+        h = host(["AAA", "BBB"], limit=1)
+        picked = h._select_games_for_display(slate(False), ["AAA", "BBB"])
+        assert [g["id"] for g in picked] == ["s1"]
+
+    def test_games_without_an_id_are_never_duplicates(self):
+        games = [match("1", "2"), match("1", "3")]
+        assert len(host(["AAA"])._select_games_for_display(games, ["AAA"])) == 2
+
+    def test_a_reused_id_is_a_duplicate(self):
+        games = [match("1", "2", id="x"), match("1", "3", id="x")]
+        assert len(host(["AAA"])._select_games_for_display(games, ["AAA"])) == 1
+
+    def test_upcoming_is_soonest_first_and_recent_newest_first(self):
+        assert pick(["CCC"], 5, False) == "s2,s3,s7,~,s9"
+        assert pick(["CCC"], 5, True) == "s2,s3,s7,~,s9"
+
+    def test_the_handed_list_is_used_not_favorite_teams(self):
+        h = host(["CCC"], limit=1)
+        assert [g["id"] for g in h._select_games_for_display(slate(False), ["AAA"])] == ["s1"]
+
+    @pytest.mark.parametrize("recent", [False, True])
+    def test_the_summary_is_logged_at_info(self, recent, caplog):
+        with caplog.at_level(logging.INFO, logger=LOG.name):
+            pick(["AAA"], 1, recent)
+        name = "_select_recent_games_for_display" if recent else "_select_games_for_display"
+        assert [r.levelno for r in caplog.records if r.funcName == name
+                and r.levelno >= logging.INFO] == [logging.INFO]
+
+
+# ---------------------------------------------------------------------------
+# Carriers and host contract
+# ---------------------------------------------------------------------------
+
+MIXINS = {
+    "SportsFavoritesMixin": ["_favorite_code", "_is_favorite_game"],
+    "SportsUpcomingFavoritesMixin": ["_select_games_for_display"],
+    "SportsRecentFavoritesMixin": ["_select_recent_games_for_display"],
+}
+
+
+def _classes():
+    tree = ast.parse(Path(sports_favorites.__file__).read_text(encoding="utf-8"))
+    return {n.name: n for n in tree.body if isinstance(n, ast.ClassDef)}
+
+
+def _self_reads(cls):
+    return {node.attr for node in ast.walk(cls)
+            if isinstance(node, ast.Attribute) and isinstance(node.ctx, ast.Load)
+            and isinstance(node.value, ast.Name) and node.value.id == "self"}
+
+
+class TestHostContract:
+    def test_each_mixin_carries_only_its_class_methods(self):
+        """So adopting one gives no manager a method it did not have."""
+        for name, methods in MIXINS.items():
+            mixin = getattr(sports_favorites, name)
+            assert sorted(n for n in vars(mixin) if not n.startswith("__")) == methods
+
+    def test_every_host_read_is_documented(self):
+        reads = set().union(*(_self_reads(c) for c in _classes().values()))
+        undocumented = sorted(n for n in reads if f"``{n}``" not in sports_favorites.__doc__)
+        assert undocumented == [], f"read but not in the host contract: {undocumented}"
+
+    def test_the_key_comes_from_sports_helpers(self):
+        """The seam stays where 3.5.0 put it; this module only calls it."""
+        assert "_favorite_key" in vars(SportsHelpersMixin)
+        assert all("_favorite_key" not in vars(getattr(sports_favorites, n)) for n in MIXINS)
+
+    def test_no_other_shared_mixin_defines_these(self):
+        from src.common import sports_display_rules, sports_shared
+        others = [sports_shared.SportsCoreSharedMixin, sports_shared.SportsRecentSharedMixin,
+                  sports_shared.SportsLiveSharedMixin, SportsHelpersMixin,
+                  sports_display_rules.SportsGameRulesMixin]
+        for methods in MIXINS.values():
+            for name in methods:
+                assert not any(name in vars(o) for o in others), name
+
+    def test_the_shared_callers_reach_it(self):
+        """_favorites_first and the live dwell ask _is_favorite_game; one body answers."""
+        from src.common.sports_display_rules import SportsGameRulesMixin
+
+        class Host(SportsGameRulesMixin, SportsFavoritesMixin, SportsHelpersMixin):
+            favorite_teams = ["aaa"]
+            game_display_duration = 15
+            non_favorite_live_game_duration = 5
+
+        assert Host()._effective_live_duration(dict(GAMES["AAA home v BBB"])) == 15
+        assert Host()._effective_live_duration(dict(GAMES["CCC v DDD"])) == 5

test/test_sports_favorites_parity.py

@@ -0,0 +1,135 @@
+"""sports_favorites still matches every plugin copy, and only nrl overrides the key.
+
+``src.common.sports_favorites`` was copied from the scoreboards once family 6
+had made each method one body in all nine: ``SportsCore._favorite_code`` and
+``_is_favorite_game``, ``SportsUpcoming._select_games_for_display`` and
+``SportsRecent._select_recent_games_for_display``. The plugins delete their
+copies once they floor on the release that ships this module. Until each has, a
+copy that changes on its own is a fix one side has and the other lacks.
+
+Point LEDMATRIX_PLUGINS at a ledmatrix-plugins checkout and each method is
+compared with every plugin copy using ``scripts/sports_drift_report.py``'s own
+normalisation (the AST with docstrings and annotations dropped), plus the
+decorators. A copy that is gone counts as adopted when the plugin's
+``sports.py`` names the module. The owner's decision that only nrl overrides
+``_favorite_key`` (with the team id) is checked too; that override stays in
+the plugin after adoption. Without the variable this skips: core CI has no
+plugins checkout.
+"""
+
+import ast
+import importlib.util
+import os
+from pathlib import Path
+
+import pytest
+
+from src.common import sports_favorites
+
+REPO = Path(__file__).resolve().parents[1]
+SPORTS = ("afl", "baseball", "basketball", "football", "hockey", "lacrosse",
+          "nrl", "soccer", "ufc")
+
+#: plugin class -> (our mixin, the methods it carries)
+CARRIERS = {
+    "SportsCore": ("SportsFavoritesMixin", ("_favorite_code", "_is_favorite_game")),
+    "SportsUpcoming": ("SportsUpcomingFavoritesMixin", ("_select_games_for_display",)),
+    "SportsRecent": ("SportsRecentFavoritesMixin", ("_select_recent_games_for_display",)),
+}
+
+#: The owner's decision (docs/SPORTS_UNIFICATION.md, family 6): the sports
+#: that name a team by something other than its abbreviation.
+OVERRIDES_FAVORITE_KEY = {"nrl"}
+
+
+def _drift_report():
+    """scripts/sports_drift_report.py, loaded by path (scripts/ is no package)."""
+    spec = importlib.util.spec_from_file_location(
+        "sports_drift_report", REPO / "scripts" / "sports_drift_report.py")
+    module = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(module)
+    return module
+
+
+DRIFT = _drift_report()
+
+
+def _plugins_root():
+    root = DRIFT.resolve_plugins_dir(os.environ.get("LEDMATRIX_PLUGINS"))
+    if root is None:
+        pytest.skip("set LEDMATRIX_PLUGINS to a ledmatrix-plugins checkout to "
+                    "compare this module against the plugin copies")
+    return root
+
+
+def _class(tree, name):
+    return next(n for n in tree.body if isinstance(n, ast.ClassDef) and n.name == name)
+
+
+def _method(cls, name):
+    return next((n for n in cls.body
+                 if isinstance(n, ast.FunctionDef) and n.name == name), None)
+
+
+def _fingerprint(node):
+    return (DRIFT._digest(node, DRIFT._Canonical()),
+            tuple(ast.unparse(d) for d in node.decorator_list))
+
+
+def _ours(mixin):
+    tree = ast.parse(Path(sports_favorites.__file__).read_text(encoding="utf-8"))
+    return _class(tree, mixin)
+
+
+def _plugin_tree(root, sport):
+    source = (root / f"{sport}-scoreboard" / "sports.py").read_text(encoding="utf-8")
+    return source, ast.parse(source)
+
+
+CASES = [(sport, cls, name) for sport in SPORTS
+         for cls, (_, names) in CARRIERS.items() for name in names]
+
+
+@pytest.mark.parametrize("sport, cls, name", CASES)
+def test_every_remaining_plugin_copy_matches(sport, cls, name):
+    source, tree = _plugin_tree(_plugins_root(), sport)
+    copy = _method(_class(tree, cls), name)
+    if copy is None:
+        assert sports_favorites.__name__ in source, (
+            f"{sport}: no {name} on {cls} and no {sports_favorites.__name__} import")
+    else:
+        ours = _method(_ours(CARRIERS[cls][0]), name)
+        assert _fingerprint(copy) == _fingerprint(ours), (
+            f"{cls}.{name} in {sport} differs from sports_favorites. "
+            f"Port the change to both, or stop treating it as shared.")
+
+
+@pytest.mark.parametrize("sport", SPORTS)
+def test_no_other_plugin_class_carries_a_copy(sport):
+    """A copy on another class (afl's old SportsUpcoming._is_favorite_game) would shadow the shared one."""
+    _, tree = _plugin_tree(_plugins_root(), sport)
+    shared = {name: cls for cls, (_, names) in CARRIERS.items() for name in names}
+    strays = [f"{node.name}.{name}" for node in tree.body if isinstance(node, ast.ClassDef)
+              for name, home in shared.items()
+              if node.name != home and _method(node, name) is not None]
+    assert strays == []
+
+
+def test_only_the_decided_sports_override_the_key():
+    root = _plugins_root()
+    overriding = {sport for sport in SPORTS
+                  if any(_method(node, "_favorite_key") is not None
+                         for node in _plugin_tree(root, sport)[1].body
+                         if isinstance(node, ast.ClassDef))}
+    assert overriding == OVERRIDES_FAVORITE_KEY
+
+
+def test_the_drift_report_still_calls_them_identical():
+    root = _plugins_root()
+    families = DRIFT.build(root, ("sports.py",))
+    rows = {(r["file"], r["family"]): r
+            for r in (DRIFT.summarise(k, v) for k, v in families.items())}
+    for _, names in CARRIERS.values():
+        for name in names:
+            row = rows.get(("sports.py", name))
+            assert row is None or row["worst_class_variants"] == 1, name

test/test_sports_game_over.py

@@ -0,0 +1,275 @@
+"""src.common.sports_game_over: behaviour, host contract and base order.
+
+The matrix is ledmatrix-plugins' ``scripts/test_game_over_check.py`` (the
+table the family 5 reconcile was checked against) folded to the three
+``FINAL_PERIOD`` values the nine scoreboards declare: None (afl, baseball,
+nrl, soccer, ufc), 4 (basketball, football, lacrosse) and 3 (hockey).
+Baseball's postponed/suspended override stays in its plugin and is not here.
+"""
+
+import ast
+import logging
+import time
+from pathlib import Path
+
+import pytest
+
+from src.common import sports_game_over
+from src.common.sports_game_over import SportsGameOverMixin
+from src.common.sports_shared import SportsLiveSharedMixin
+
+LOG = logging.getLogger("test_sports_game_over")
+
+
+def host(final_period):
+    """A live manager stand-in declaring ``FINAL_PERIOD`` as a plugin does."""
+    cls = type("Live", (SportsGameOverMixin,), {"FINAL_PERIOD": final_period})
+    h = cls()
+    h.logger = LOG
+    return h
+
+
+MISSING = object()  # the key is absent from the game dict
+
+
+def game(period_text="", period=MISSING, clock=MISSING, away="1", home="2"):
+    g = {"away_abbr": "AWY", "home_abbr": "HOM", "away_score": away,
+         "home_score": home, "period_text": period_text}
+    if period is not MISSING:
+        g["period"] = period
+    if clock is not MISSING:
+        g["clock"] = clock
+    return g
+
+
+# ---------------------------------------------------------------------------
+# The matrix: clock x period, for each FINAL_PERIOD. Scores 1-2.
+# ---------------------------------------------------------------------------
+
+FINAL_PERIODS = (None, 4, 3)
+PERIODS = (MISSING, 1, 2, 3, 4, 5, 6)
+CLOCKS = {"12:00": "12:00", "0:00": "0:00", ":00": ":00", "0.0": "0.0",
+          "-": "-", "''": "", "None": None, "missing": MISSING}
+
+#: The period text each ESPN status carries. Only "Final" contains "final";
+#: the method reads no status, so every other text answers the same row.
+LIVE_TEXTS = {
+    "in progress": lambda p: "" if p is MISSING else f"P{p}",
+    "end of period": lambda p: "" if p is MISSING else f"End P{p}",
+    "halftime": lambda p: "Halftime",
+    "end of round": lambda p: "" if p is MISSING else f"End R{p}",
+    "postponed": lambda p: "Postponed",
+}
+
+#: clock -> one cell per period (missing, 1..6) for FINAL_PERIOD None, 4, 3.
+EXPECTED_LIVE = {
+    "12:00": "....... ....... .......",
+    "0:00": "....... ....YYY ...YYYY",
+    ":00": "....... ....YYY ...YYYY",
+    "0.0": "....... ....... .......",
+    "-": "....... ....... .......",
+    "''": "....... ....... .......",
+    "None": "....... ....... .......",
+    "missing": "....... ....... .......",
+}
+
+
+def row(text_for, clock):
+    return " ".join(
+        "".join("Y" if host(fp)._is_game_really_over(game(text_for(p), p, clock)) else "."
+                for p in PERIODS)
+        for fp in FINAL_PERIODS)
+
+
+@pytest.mark.parametrize("status", sorted(LIVE_TEXTS))
+@pytest.mark.parametrize("clock_label", sorted(CLOCKS))
+def test_a_live_period_text(status, clock_label):
+    assert row(LIVE_TEXTS[status], CLOCKS[clock_label]) == EXPECTED_LIVE[clock_label]
+
+
+@pytest.mark.parametrize("clock_label", sorted(CLOCKS))
+def test_a_final_period_text_is_always_over(clock_label):
+    assert row(lambda p: "Final", CLOCKS[clock_label]) == "YYYYYYY YYYYYYY YYYYYYY"
+
+
+#: label -> (game, one cell per FINAL_PERIOD None, 4, 3)
+EDGES = {
+    "period_text None, P4 0:00": (game(None, 4, "0:00"), ".YY"),
+    "period None, 0:00": (game("", None, "0:00"), "..."),
+    "period 'OT', 0:00": (game("OT", "OT", "0:00"), "..."),
+    "period '4' (str), 0:00": (game("P4", "4", "0:00"), ".YY"),
+    "clock int 0, P4": (game("P4", 4, 0), "..."),
+    "clock float 0.0, P4": (game("P4", 4, 0.0), "..."),
+    "clock ' 0:00 ', P4": (game("P4", 4, " 0:00 "), ".YY"),
+    "clock '00:00', P4": (game("P4", 4, "00:00"), "..."),
+    "period_text 'Final/OT', P5 0:00": (game("Final/OT", 5, "0:00"), "YYY"),
+    "period_text 'FINAL', P1 12:00": (game("FINAL", 1, "12:00"), "YYY"),
+}
+
+
+@pytest.mark.parametrize("label", sorted(EDGES))
+def test_edge_shapes(label):
+    g, want = EDGES[label]
+    got = "".join("Y" if host(fp)._is_game_really_over(dict(g)) else "." for fp in FINAL_PERIODS)
+    assert got == want
+
+
+# ---------------------------------------------------------------------------
+# The tie guard: level at 0:00 is overtime, not the end.
+# ---------------------------------------------------------------------------
+
+class TestTieGuard:
+    @pytest.mark.parametrize("fp,period", [(4, 4), (4, 5), (3, 3), (3, 4), (3, 5)])
+    def test_level_at_zero_is_not_over(self, fp, period):
+        assert host(fp)._is_game_really_over(game("", period, "0:00", "2", "2")) is False
+
+    def test_level_scores_compare_as_numbers(self):
+        assert host(4)._is_game_really_over(game("", 4, "0:00", 2, "2")) is False
+        assert host(4)._is_game_really_over(game("", 4, "0:00", " 2 ", "2")) is False
+
+    def test_a_game_that_ends_level_ends_on_final(self):
+        assert host(4)._is_game_really_over(game("Final/OT", 5, "0:00", "2", "2")) is True
+
+    def test_level_before_the_final_period_was_never_over(self):
+        assert host(4)._is_game_really_over(game("", 3, "0:00", "2", "2")) is False
+
+    @pytest.mark.parametrize("away,home", [
+        (MISSING, MISSING), (None, None), ("", ""), ("2", None),
+        ("2.0", "2.0"), ({"value": 2}, {"value": 2}), ("inf", "inf"),
+    ])
+    def test_an_unreadable_score_leaves_it_to_the_clock(self, away, home):
+        g = game("", 4, "0:00")
+        for key, value in (("away_score", away), ("home_score", home)):
+            if value is MISSING:
+                del g[key]
+            else:
+                g[key] = value
+        assert host(4)._is_game_really_over(g) is True
+
+    def test_float_infinity_does_not_raise(self):
+        assert host(4)._is_game_really_over(
+            game("", 4, "0:00", float("inf"), float("inf"))) is True
+
+
+# ---------------------------------------------------------------------------
+# ufc: ESPN MMA payloads, as ufc's _extract_game_details stores them
+# (ledmatrix-plugins plugins/ufc-scoreboard/test/fixtures/espn_mma_round_states.json).
+# ---------------------------------------------------------------------------
+
+UFC_RECORDED = {
+    "in_round_3_of_3": ("R3", 3, "1:21"),
+    "break_after_round_1": ("R1", 1, "-"),
+    "end_of_round_after_stoppage": ("R2", 2, "0:51"),
+    "walkouts_five_rounder": ("", 0, "-"),
+    "final_five_round_decision": ("R5", 5, "5:00"),
+    "final_five_round_stoppage": ("R5", 5, "1:38"),
+    "final_three_round_decision": ("R3", 3, "5:00"),
+    "final_three_round_stoppage": ("R2", 2, "4:07"),
+    "break_after_round_4_of_5": ("R4", 4, "-"),
+    "end_of_round_5_awaiting_decision": ("R5", 5, "-"),
+}
+
+
+class TestUfc:
+    @pytest.mark.parametrize("name", sorted(UFC_RECORDED))
+    def test_no_recorded_state_is_over_here(self, name):
+        """A finished bout leaves the live list on is_final, before this is asked."""
+        text, period, clock = UFC_RECORDED[name]
+        assert host(None)._is_game_really_over(game(text, period, clock, "0", "0")) is False
+
+    @pytest.mark.parametrize("fp", FINAL_PERIODS)
+    def test_a_round_break_dash_is_never_a_zero_clock(self, fp):
+        assert host(fp)._is_game_really_over(game("R4", 4, "-", "1", "2")) is False
+
+    @pytest.mark.parametrize("clock", ["0:00", None, MISSING])
+    def test_the_horn_does_not_end_a_bout(self, clock):
+        assert host(None)._is_game_really_over(game("R5", 5, clock, "1", "2")) is False
+
+
+# ---------------------------------------------------------------------------
+# Wiring: the default, overrides, and the live mixin's caller.
+# ---------------------------------------------------------------------------
+
+def test_the_default_is_no_clock_rule():
+    assert SportsGameOverMixin.FINAL_PERIOD is None
+
+
+def test_an_override_defers_through_super():
+    """baseball's BaseballLive: its own check first, then the shared one."""
+
+    class Baseballish(SportsGameOverMixin):
+        logger = LOG
+
+        def _is_game_really_over(self, game):
+            if game.get("status") == "status_postponed":
+                return True
+            return super()._is_game_really_over(game)
+
+    b = Baseballish()
+    assert b._is_game_really_over(dict(game("", 6, "0:00"), status="status_postponed")) is True
+    assert b._is_game_really_over(game("", 6, "0:00")) is False
+    assert b._is_game_really_over(game("Final", 9, None)) is True
+
+
+class _Live(SportsGameOverMixin, SportsLiveSharedMixin):
+    """A SportsLive stand-in in the documented base order."""
+
+    FINAL_PERIOD = 4
+
+    def __init__(self):
+        self.logger = LOG
+        self.stale_game_timeout = 600
+        self.game_update_timestamps = {}
+
+
+class TestBaseOrder:
+    def test_the_documented_order_resolves_this_method(self):
+        assert _Live._is_game_really_over is SportsGameOverMixin._is_game_really_over
+        mro = _Live.__mro__
+        assert mro.index(SportsGameOverMixin) < mro.index(SportsLiveSharedMixin)
+
+    def test_neither_shared_mixin_defines_it(self):
+        """So the base order cannot change which body runs."""
+        from src.common.sports_shared import SportsCoreSharedMixin
+        for mixin in (SportsLiveSharedMixin, SportsCoreSharedMixin):
+            assert "_is_game_really_over" not in vars(mixin)
+
+    def test_detect_stale_games_drops_an_over_game_through_it(self):
+        live = _Live()
+        live.game_update_timestamps = {"over": {"last_seen": time.time()},
+                                       "on": {"last_seen": time.time()}}
+        games = [dict(game("", 4, "0:00"), id="over"),
+                 dict(game("", 4, "0:00", "2", "2"), id="on")]
+        live._detect_stale_games(games)
+        assert [g["id"] for g in games] == ["on"]
+        assert "over" not in live.game_update_timestamps
+
+    def test_the_class_value_wins_over_the_default(self):
+        assert _Live().FINAL_PERIOD == 4
+        assert _Live()._is_game_really_over(game("", 4, "0:00")) is True
+
+
+# ---------------------------------------------------------------------------
+# Host contract
+# ---------------------------------------------------------------------------
+
+def _self_reads():
+    tree = ast.parse(Path(sports_game_over.__file__).read_text(encoding="utf-8"))
+    cls = next(n for n in tree.body
+               if isinstance(n, ast.ClassDef) and n.name == "SportsGameOverMixin")
+    return {node.attr for node in ast.walk(cls)
+            if isinstance(node, ast.Attribute) and isinstance(node.ctx, ast.Load)
+            and isinstance(node.value, ast.Name) and node.value.id == "self"}
+
+
+class TestHostContract:
+    def test_every_host_read_is_documented(self):
+        undocumented = sorted(n for n in _self_reads()
+                              if f"``{n}``" not in sports_game_over.__doc__)
+        assert undocumented == [], f"read but not in the host contract: {undocumented}"
+
+    def test_the_mixin_creates_no_state(self):
+        assert "__init__" not in vars(SportsGameOverMixin)
+        assert not hasattr(SportsGameOverMixin, "logger")
+        assert sorted(n for n in vars(SportsGameOverMixin) if not n.startswith("__")) == [
+            "FINAL_PERIOD", "_is_game_really_over"]

test/test_sports_game_over_parity.py

@@ -0,0 +1,123 @@
+"""sports_game_over still matches every plugin copy, and each plugin's FINAL_PERIOD.
+
+``SportsGameOverMixin._is_game_really_over`` was copied from the scoreboards'
+``SportsLive._is_game_really_over`` once family 5 had made the nine copies one
+body. The plugins delete their copies once they floor on the release that
+ships this module. Until each has, a copy that changes on its own is a fix one
+side has and the other lacks.
+
+Point LEDMATRIX_PLUGINS at a ledmatrix-plugins checkout and the method is
+compared with every plugin copy using ``scripts/sports_drift_report.py``'s own
+normalisation (the AST with docstrings and annotations dropped), plus the
+decorators. A copy that is gone counts as adopted when the plugin's
+``sports.py`` names the module. Each plugin's ``SportsLive.FINAL_PERIOD`` is
+compared with the value the owner decided for its sport, which stays in the
+plugin after adoption. Without the variable this skips: core CI has no plugins
+checkout.
+"""
+
+import ast
+import importlib.util
+import os
+from pathlib import Path
+
+import pytest
+
+from src.common import sports_game_over
+
+REPO = Path(__file__).resolve().parents[1]
+
+#: The owner's decision (docs/SPORTS_UNIFICATION.md, family 5): the period
+#: from which a 0:00 clock ends a game, None where the clock never does.
+FINAL_PERIOD = {
+    "afl": None, "baseball": None, "basketball": 4, "football": 4,
+    "hockey": 3, "lacrosse": 4, "nrl": None, "soccer": None, "ufc": None,
+}
+NAME = "_is_game_really_over"
+
+
+def _drift_report():
+    """scripts/sports_drift_report.py, loaded by path (scripts/ is no package)."""
+    spec = importlib.util.spec_from_file_location(
+        "sports_drift_report", REPO / "scripts" / "sports_drift_report.py")
+    module = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(module)
+    return module
+
+
+DRIFT = _drift_report()
+
+
+def _plugins_root():
+    root = DRIFT.resolve_plugins_dir(os.environ.get("LEDMATRIX_PLUGINS"))
+    if root is None:
+        pytest.skip("set LEDMATRIX_PLUGINS to a ledmatrix-plugins checkout to "
+                    "compare this module against the plugin copies")
+    return root
+
+
+def _class(tree, name):
+    return next(n for n in tree.body if isinstance(n, ast.ClassDef) and n.name == name)
+
+
+def _method(cls):
+    return next((n for n in cls.body
+                 if isinstance(n, ast.FunctionDef) and n.name == NAME), None)
+
+
+def _fingerprint(node):
+    return (DRIFT._digest(node, DRIFT._Canonical()),
+            tuple(ast.unparse(d) for d in node.decorator_list))
+
+
+def _final_period(cls):
+    for node in cls.body:
+        if (isinstance(node, (ast.Assign, ast.AnnAssign)) and node.value is not None):
+            target = node.targets[0] if isinstance(node, ast.Assign) else node.target
+            if isinstance(target, ast.Name) and target.id == "FINAL_PERIOD":
+                return ast.literal_eval(node.value)
+    raise AssertionError("SportsLive declares no FINAL_PERIOD")
+
+
+def _ours():
+    tree = ast.parse(Path(sports_game_over.__file__).read_text(encoding="utf-8"))
+    return _class(tree, "SportsGameOverMixin")
+
+
+def test_the_mixin_holds_one_method_and_the_default():
+    names = sorted(n.name if isinstance(n, ast.FunctionDef) else n.target.id
+                   for n in _ours().body if isinstance(n, (ast.FunctionDef, ast.AnnAssign))
+                   and (isinstance(n, ast.FunctionDef) or n.value is not None))
+    assert names == ["FINAL_PERIOD", NAME]
+    assert _final_period(_ours()) is None
+
+
+@pytest.mark.parametrize("sport", sorted(FINAL_PERIOD))
+def test_every_remaining_plugin_copy_matches(sport):
+    root = _plugins_root()
+    source = (root / f"{sport}-scoreboard" / "sports.py").read_text(encoding="utf-8")
+    live = _class(ast.parse(source), "SportsLive")
+    copy = _method(live)
+    if copy is None:
+        assert sports_game_over.__name__ in source, (
+            f"{sport}: no {NAME} on SportsLive and no {sports_game_over.__name__} import")
+    else:
+        assert _fingerprint(copy) == _fingerprint(_method(_ours())), (
+            f"{NAME} in {sport} differs from sports_game_over. "
+            f"Port the change to both, or stop treating it as shared.")
+
+
+@pytest.mark.parametrize("sport", sorted(FINAL_PERIOD))
+def test_every_plugin_declares_its_final_period(sport):
+    root = _plugins_root()
+    source = (root / f"{sport}-scoreboard" / "sports.py").read_text(encoding="utf-8")
+    assert _final_period(_class(ast.parse(source), "SportsLive")) == FINAL_PERIOD[sport]
+
+
+def test_the_drift_report_still_calls_it_identical():
+    root = _plugins_root()
+    families = DRIFT.build(root, ("sports.py",))
+    rows = {(r["file"], r["family"]): r
+            for r in (DRIFT.summarise(k, v) for k, v in families.items())}
+    row = rows.get(("sports.py", NAME))
+    assert row is None or row["worst_class_variants"] == 1

test/test_sports_helpers.py

@@ -8,7 +8,9 @@ loses those tests with it.
 The parity class is what keeps "byte-identical" true after this lands. Point
 LEDMATRIX_PLUGINS at a ledmatrix-plugins checkout and every promoted body is
 compared, as a docstring-stripped AST, against every plugin copy that carries
-it. Without the variable it skips rather than fails, since core CI has no
+it. A copy that is gone counts as adopted when the plugin imports
+src.common.sports_helpers (plugins#563/#564 did that for every scoreboard).
+Without the variable it skips rather than fails, since core CI has no
 plugins checkout; ledmatrix-plugins CI runs the same comparison against core
 (scripts/check_sports_helpers_parity.py, ledmatrix-plugins#495).
 """
@@ -572,6 +574,24 @@ def _core_definitions():
     return out
 
 
+def _sports_source(root, sport):
+    return (root / f"{sport}-scoreboard" / "sports.py").read_text(encoding="utf-8")
+
+
+def _adopted(source):
+    """Gone is fine once the plugin uses the module; otherwise the finder is
+    not seeing its copy."""
+    name = sports_helpers.__name__
+    for node in ast.walk(ast.parse(source)):
+        if isinstance(node, ast.ImportFrom):
+            if node.module == name or any(
+                    f"{node.module}.{a.name}" == name for a in node.names):
+                return True
+        elif isinstance(node, ast.Import) and any(a.name == name for a in node.names):
+            return True
+    return False
+
+
 class TestParityWithPlugins:
     @pytest.mark.parametrize("name", sorted(PROMOTED))
     def test_body_matches_every_plugin_copy(self, name):
@@ -580,11 +600,11 @@ class TestParityWithPlugins:
         ours = _dump(_core_definitions()[name])
         drifted, missing = [], []
         for sport in carriers:
-            defs = _definitions(ast.parse(
-                (root / f"{sport}-scoreboard" / "sports.py").read_text(encoding="utf-8")))
-            theirs = defs[where].get(plugin_name)
+            source = _sports_source(root, sport)
+            theirs = _definitions(ast.parse(source))[where].get(plugin_name)
             if theirs is None:
-                missing.append(sport)
+                if not _adopted(source):
+                    missing.append(sport)
             elif _dump(theirs) != ours:
                 drifted.append(sport)
         assert missing == [], f"{plugin_name} no longer in: {missing}"
@@ -594,10 +614,20 @@ class TestParityWithPlugins:
 
     @pytest.mark.parametrize("sport", SCOREBOARDS)
     def test_constants_match(self, sport):
-        root = _plugins_root()
-        defs = _definitions(ast.parse(
-            (root / f"{sport}-scoreboard" / "sports.py").read_text(encoding="utf-8")))
-        assert ast.literal_eval(defs["module"]["_MIN_WINDOW_DAYS"].value) == MIN_WINDOW_DAYS
-        assert ast.literal_eval(defs["module"]["_MAX_WINDOW_DAYS"].value) == MAX_WINDOW_DAYS
-        gap = defs["SportsCore"]["_DWELL_REENTRY_GAP_SECONDS"].value
-        assert math.isclose(ast.literal_eval(gap), SportsHelpersMixin._DWELL_REENTRY_GAP_SECONDS)
+        source = _sports_source(_plugins_root(), sport)
+        defs = _definitions(ast.parse(source))
+        expected = {
+            ("module", "_MIN_WINDOW_DAYS"): MIN_WINDOW_DAYS,
+            ("module", "_MAX_WINDOW_DAYS"): MAX_WINDOW_DAYS,
+            ("SportsCore", "_DWELL_REENTRY_GAP_SECONDS"):
+                SportsHelpersMixin._DWELL_REENTRY_GAP_SECONDS,
+        }
+        missing = []
+        for (where, name), value in expected.items():
+            node = defs[where].get(name)
+            if node is None:
+                if not _adopted(source):
+                    missing.append(name)
+            else:
+                assert math.isclose(ast.literal_eval(node.value), value), name
+        assert missing == [], f"not found in {sport}: {missing}"

test/test_sports_shared.py

@@ -465,6 +465,136 @@ class TestLiveMixin:
         # The safety property that makes it correct: 30s beats 600s.
         assert h._idle_live_interval() == h.update_interval
 
+    # ---- every pending kickoff is honoured, not just the first ------------
+    #
+    # One stored kickoff held the slot through its grace and refused every
+    # later one; a later one that had passed by the time the grace ended was
+    # refused again as "already past". So of two favourites kicking off ten
+    # minutes apart, the second lost its grace: if ESPN had not flipped it live
+    # by the end of the FIRST game's grace, the back-off returned to its
+    # ceiling and the game was noticed up to that late. That bites whenever the
+    # first game is not live by then -- a rain delay, a postponement, ESPN slow
+    # to flip it -- since a live first game keeps the live cadence anyway.
+
+    @staticmethod
+    def _replay(monkeypatch, kickoffs, flips, until, poll=30, ceiling=900):
+        """Drive a live manager's idle loop over a schedule on a fake clock.
+
+        ``kickoffs`` are start offsets in seconds from t=0 (the first look),
+        ``flips`` how long after its start ESPN reports each game live (None:
+        postponed, never live). Every
+        look offers each not-yet-live game, as the live loop does, then sleeps
+        for whatever the back-off returns. Returns, per game, how long after it
+        went live it was first seen live -- None if never.
+        """
+        clock = [1_800_000_000.0]
+        monkeypatch.setattr(sports_shared.time, "time", lambda: clock[0])
+        h = _LiveHost(no_data_interval=300)
+        h.live_idle_max_interval = ceiling
+        h.update_interval = poll
+        h._empty_live_streak = 30          # idle all morning: at the ceiling
+        t0 = clock[0]
+        seen = [None] * len(kickoffs)
+        while clock[0] - t0 < until:
+            now = clock[0] - t0
+            live = [f is not None and k + f <= now for k, f in zip(kickoffs, flips)]
+            for i, is_live in enumerate(live):
+                if is_live and seen[i] is None:
+                    seen[i] = now - (kickoffs[i] + flips[i])
+                start = datetime.fromtimestamp(t0 + kickoffs[i], tz=timezone.utc)
+                h._note_scheduled_start_candidate(
+                    {"is_live": is_live, "is_halftime": False,
+                     "start_time_utc": start})
+            # A real board keeps polling at the live cadence while anything is
+            # live; a game here stays live for an hour after it flips.
+            on = any(f is not None and k + f <= now < k + f + 3600
+                     for k, f in zip(kickoffs, flips))
+            h._note_live_fetch(on)
+            clock[0] += poll if on else h._idle_live_interval()
+            assert len(getattr(h, "_later_scheduled_starts", None) or ())                 <= sports_shared._KICKOFF_QUEUE_MAX
+        return seen
+
+    @pytest.mark.parametrize("kickoffs,flips", [
+        # (start offsets, ESPN's flip delay per game), both in seconds.
+        pytest.param([1800], [120], id="one kickoff, flipped 2 min late"),
+        pytest.param([1800, 2400], [0, 840],
+                     id="first live on time, the second flipped 14 min late"),
+        pytest.param([1800, 2400], [None, 840],
+                     id="first postponed, the second 10 min later flipped 14 min late"),
+        pytest.param([1800, 2400], [1200, 840],
+                     id="first in a 20 min delay, the second flipped 14 min late"),
+        pytest.param([1800, 2100, 2520], [None, None, 600],
+                     id="three inside one grace, the last flipped 10 min late"),
+        pytest.param([1800, 1800, 2400], [None, None, 700],
+                     id="two at the same time, then one 10 min later"),
+        pytest.param([1800, 2700], [None, 840],
+                     id="second kickoff 15 min later, flipped 14 min late"),
+        pytest.param([1800 + 60 * i for i in range(20)],
+                     [None] * 19 + [840],
+                     id="twenty kickoffs a minute apart overflow the queue"),
+    ])
+    def test_every_pending_kickoff_gets_its_grace(self, monkeypatch, kickoffs, flips):
+        seen = self._replay(monkeypatch, kickoffs, flips,
+                            until=max(kickoffs) + 3 * 3600)
+        late = [s for s, f in zip(seen, flips)
+                if f is not None and (s is None or s > 30)]
+        assert not late, "games noticed late (s after going live): %r" % (seen,)
+
+    def test_a_kickoff_that_never_flips_costs_one_grace_then_backs_off(self, monkeypatch):
+        # A postponed game keeps the live cadence for its grace and no longer:
+        # remembering more kickoffs must not pin the poll to dead ones.
+        clock = [1_800_000_000.0]
+        monkeypatch.setattr(sports_shared.time, "time", lambda: clock[0])
+        h = self._idle_host()
+        t0 = clock[0]
+        for offset in (600, 900):
+            h._note_scheduled_start_candidate(
+                {"start_time_utc": datetime.fromtimestamp(t0 + offset, tz=timezone.utc)})
+        clock[0] = t0 + 900 + sports_shared._KICKOFF_GRACE_SECONDS - 1
+        assert h._idle_live_interval() == h.update_interval
+        clock[0] = t0 + 900 + sports_shared._KICKOFF_GRACE_SECONDS + 1
+        assert h._idle_live_interval() == 900
+        assert not getattr(h, "_later_scheduled_starts", None)
+
+    def test_a_queued_kickoff_past_its_own_grace_is_skipped(self, monkeypatch):
+        # After a long sleep (or a run of looks that never woke the manager)
+        # several queued kickoffs may have gone stale at once. The one still
+        # inside its grace must win, not the first stale one in the queue.
+        clock = [1_800_000_000.0]
+        monkeypatch.setattr(sports_shared.time, "time", lambda: clock[0])
+        h = self._idle_host()
+        t0 = clock[0]
+        for offset in (600, 700, 1500):
+            h._note_scheduled_start_candidate(
+                {"start_time_utc": datetime.fromtimestamp(t0 + offset, tz=timezone.utc)})
+        clock[0] = t0 + 1500 + 150     # 600 and 700 are past their grace
+        assert h._idle_live_interval() == h.update_interval
+        assert h._next_scheduled_start_ts == t0 + 1500
+
+    def test_the_queue_keeps_the_earliest_kickoffs(self, monkeypatch):
+        clock = [1_800_000_000.0]
+        monkeypatch.setattr(sports_shared.time, "time", lambda: clock[0])
+        h = self._idle_host()
+        t0 = clock[0]
+        cap = sports_shared._KICKOFF_QUEUE_MAX
+        for offset in reversed(range(1, cap + 6)):          # latest first
+            h._note_scheduled_start_candidate(
+                {"start_time_utc": datetime.fromtimestamp(t0 + 600 * offset, tz=timezone.utc)})
+        assert h._next_scheduled_start_ts == t0 + 600
+        assert h._later_scheduled_starts == [t0 + 600 * i for i in range(2, cap + 2)]
+
+    def test_a_kickoff_offered_twice_is_kept_once(self, monkeypatch):
+        clock = [1_800_000_000.0]
+        monkeypatch.setattr(sports_shared.time, "time", lambda: clock[0])
+        h = self._idle_host()
+        t0 = clock[0]
+        for _ in range(3):
+            for offset in (600, 1200):
+                h._note_scheduled_start_candidate(
+                    {"start_time_utc": datetime.fromtimestamp(t0 + offset, tz=timezone.utc)})
+        assert h._next_scheduled_start_ts == t0 + 600
+        assert h._later_scheduled_starts == [t0 + 1200]
+
     def test_finding_a_live_game_resets_the_streak(self):
         h = _LiveHost()
         h._note_live_fetch(False)

test/test_state_stream_readers.py

@@ -612,6 +612,12 @@ class TestEndToEnd:
         cached['display_current_state'] = {'mode': 'from-cache', 'last_updated': 1}
         path = str(tmp_path / 'control.sock')
         monkeypatch.setenv(c.SOCKET_PATH_ENV, path)
+        # The display is this process, and its render loop is beating: the
+        # cache is then still its answer once the socket goes.
+        heartbeat = tmp_path / 'display-heartbeat.json'
+        heartbeat.write_text(json.dumps({'pid': os.getpid(), 'mono': time.monotonic(),
+                                         'wall': time.time()}))
+        monkeypatch.setattr(display_watchdog, 'HEARTBEAT_PATH', str(heartbeat))
         hub = _hub_with_everything()
         server = ControlServer(path, state_hub=hub, keepalive=0.2)
         assert server.start()
@@ -638,3 +644,8 @@ class TestEndToEnd:
                 break
             time.sleep(0.05)
         assert (data['mode'], data['source']) == ('from-cache', 'cache')
+        # Stopped: systemd takes the heartbeat's directory with it, and the
+        # cache's last answer is no longer anyone's.
+        heartbeat.unlink()
+        data = _data(client, '/api/v3/display/current-status')
+        assert (data['mode'], data['source']) == (None, 'cache')

test/test_store_update_keeps_local_files.py

@@ -0,0 +1,244 @@
+"""A plugin update must keep the files the plugin wrote beside itself.
+
+Field incident, 2026-10-04: updating calendar 1.2.9 -> 1.2.12 from the web UI
+replaced plugin-repos/calendar/ with the fresh download and deleted the old
+copy -- and with it token.pickle and credentials.json, the plugin's Google
+OAuth files. No release contains them (the repo gitignores them), so the hot
+reload logged "Credentials file not found" and the calendar stayed broken
+until the files were restored by hand.
+
+Both update routes are covered: a monorepo plugin (registry ``plugin_path``),
+which is reinstalled into a fresh directory, and a plugin installed from its
+own git repository, which is updated with ``git pull`` after an auto-stash.
+"""
+
+import json
+import shutil
+import subprocess
+
+import pytest
+
+from src.plugin_system.plugin_local_files import (
+    is_known_state_file, local_files_to_keep,
+)
+from src.plugin_system.store_manager import PluginStoreManager
+
+PLUGIN_ID = "calendar"
+
+
+def _manifest(version):
+    return {"id": PLUGIN_ID, "name": "Calendar", "class_name": "CalendarPlugin",
+            "display_modes": ["calendar"], "version": version}
+
+
+def _write_release(target, version):
+    """What a download of ``version`` puts on disk."""
+    target.mkdir(parents=True, exist_ok=True)
+    (target / "manifest.json").write_text(json.dumps(_manifest(version)))
+    (target / "manager.py").write_text(f"VERSION = {version!r}\n")
+    (target / ".gitignore").write_text("credentials.json\ntoken.pickle\ncache/\n")
+
+
+def _drop_local_files(plugin_dir):
+    """What the plugin writes at runtime: OAuth files plus cached state."""
+    (plugin_dir / "token.pickle").write_bytes(b"\x80\x04oauth-token")
+    (plugin_dir / "credentials.json").write_text('{"installed": {}}')
+    (plugin_dir / "cache").mkdir()
+    (plugin_dir / "cache" / "events.json").write_text("[]")
+
+
+def _assert_local_files_kept(plugin_dir):
+    assert (plugin_dir / "token.pickle").read_bytes() == b"\x80\x04oauth-token"
+    assert (plugin_dir / "credentials.json").read_text() == '{"installed": {}}'
+    assert (plugin_dir / "cache" / "events.json").read_text() == "[]"
+
+
+def _leftover_backups(plugins_dir):
+    return [p.name for p in plugins_dir.iterdir() if "standalone-backup" in p.name]
+
+
+@pytest.fixture
+def store(tmp_path, monkeypatch):
+    mgr = PluginStoreManager(
+        plugins_dir=str(tmp_path / "plugin-repos"),
+        uninstalled_registry_path=str(tmp_path / "uninstalled.json"))
+    mgr.plugins_dir.mkdir(parents=True, exist_ok=True)
+    monkeypatch.setattr(mgr, "_install_dependencies", lambda *a, **k: True)
+    monkeypatch.setattr(mgr, "fetch_registry", lambda *a, **k: {"plugins": []})
+    return mgr
+
+
+class TestMonorepoUpdate:
+    @pytest.fixture
+    def installed(self, store, monkeypatch):
+        registry_entry = {
+            "id": PLUGIN_ID, "repo": "https://github.com/ChuckBuilds/ledmatrix-plugins",
+            "plugin_path": "plugins/calendar", "branch": "main",
+            "latest_version": "1.2.9",
+        }
+        monkeypatch.setattr(store, "get_plugin_info", lambda *a, **k: registry_entry)
+        release = {"version": "1.2.9"}
+
+        def fake_monorepo_download(download_url, plugin_subpath, target):
+            assert plugin_subpath == "plugins/calendar"
+            _write_release(target, release["version"])
+            return True
+
+        monkeypatch.setattr(store, "_install_from_monorepo", fake_monorepo_download)
+        assert store.install_plugin(PLUGIN_ID) is True
+
+        def publish(version):
+            registry_entry["latest_version"] = release["version"] = version
+        return store, store.plugins_dir / PLUGIN_ID, publish
+
+    def test_update_keeps_token_and_gitignored_files(self, installed):
+        store, plugin_dir, publish = installed
+        _drop_local_files(plugin_dir)
+
+        publish("1.2.12")
+        assert store.update_plugin(PLUGIN_ID) is True
+
+        assert json.loads((plugin_dir / "manifest.json").read_text())["version"] == "1.2.12"
+        _assert_local_files_kept(plugin_dir)
+        assert _leftover_backups(store.plugins_dir) == []
+
+    def test_token_is_kept_even_when_the_release_does_not_gitignore_it(self, installed):
+        store, plugin_dir, publish = installed
+        (plugin_dir / ".gitignore").unlink()
+        (plugin_dir / "token.pickle").write_bytes(b"tok")
+        (plugin_dir / "config_secrets.json").write_text("{}")
+
+        publish("1.2.12")
+        assert store.update_plugin(PLUGIN_ID) is True
+
+        assert (plugin_dir / "token.pickle").read_bytes() == b"tok"
+        assert (plugin_dir / "config_secrets.json").read_text() == "{}"
+
+    def test_release_content_wins_and_old_code_is_not_carried(self, installed):
+        store, plugin_dir, publish = installed
+        # A file the old copy had that the new release dropped, byte code, and
+        # an old copy of a file the new release also ships.
+        (plugin_dir / "removed_module.py").write_text("OLD = True\n")
+        (plugin_dir / "__pycache__").mkdir()
+        (plugin_dir / "__pycache__" / "manager.cpython-313.pyc").write_bytes(b"pyc")
+
+        publish("1.2.12")
+        assert store.update_plugin(PLUGIN_ID) is True
+
+        assert not (plugin_dir / "removed_module.py").exists()
+        assert not (plugin_dir / "__pycache__").exists()
+        assert "1.2.12" in (plugin_dir / "manager.py").read_text()
+
+    def test_reinstall_over_an_existing_copy_keeps_them_too(self, installed):
+        store, plugin_dir, publish = installed
+        _drop_local_files(plugin_dir)
+
+        assert store.install_plugin(PLUGIN_ID) is True
+
+        _assert_local_files_kept(plugin_dir)
+        assert _leftover_backups(store.plugins_dir) == []
+
+
+class TestInstallFromUrlReplace:
+    def test_replacing_an_installed_copy_keeps_the_token(self, store, monkeypatch):
+        plugin_dir = store.plugins_dir / PLUGIN_ID
+        _write_release(plugin_dir, "1.0.0")
+        _drop_local_files(plugin_dir)
+
+        def fake_clone(repo_url, target, branches):
+            _write_release(target, "2.0.0")
+            return "main"
+
+        monkeypatch.setattr(store, "_install_via_git", fake_clone)
+        result = store.install_from_url(
+            "https://github.com/example/ledmatrix-calendar", plugin_id=PLUGIN_ID)
+
+        assert result["success"] is True
+        assert json.loads((plugin_dir / "manifest.json").read_text())["version"] == "2.0.0"
+        _assert_local_files_kept(plugin_dir)
+
+
+def _git(*args, cwd):
+    subprocess.run(["git", "-c", "user.email=t@example.com", "-c", "user.name=t",
+                    "-c", "core.autocrlf=false", *args],
+                   cwd=cwd, check=True, capture_output=True)
+
+
+@pytest.mark.skipif(shutil.which("git") is None, reason="git not installed")
+class TestGitRepoUpdate:
+    @pytest.fixture
+    def cloned(self, store, tmp_path, monkeypatch):
+        monkeypatch.setattr(store, "get_plugin_info", lambda *a, **k: None)
+        upstream = tmp_path / "upstream"
+        _write_release(upstream, "1.0.0")
+        # This repo does NOT gitignore the token: an untracked, non-ignored
+        # file is exactly what `git stash push -u` used to sweep away.
+        (upstream / ".gitignore").write_text("cache/\n")
+        _git("init", "-q", "-b", "main", cwd=upstream)
+        _git("add", ".", cwd=upstream)
+        _git("commit", "-qm", "1.0.0", cwd=upstream)
+
+        plugin_dir = store.plugins_dir / PLUGIN_ID
+        _git("clone", "-q", str(upstream), str(plugin_dir), cwd=tmp_path)
+
+        def publish(version):
+            (upstream / "manifest.json").write_text(json.dumps(_manifest(version)))
+            _git("commit", "-qam", version, cwd=upstream)
+        return store, plugin_dir, publish
+
+    def test_pull_update_keeps_untracked_token(self, cloned):
+        store, plugin_dir, publish = cloned
+        _drop_local_files(plugin_dir)
+        # An unrelated untracked file, so the update really does stash.
+        (plugin_dir / "notes.txt").write_text("scratch")
+
+        publish("1.1.0")
+        assert store.update_plugin(PLUGIN_ID) is True
+
+        assert json.loads((plugin_dir / "manifest.json").read_text())["version"] == "1.1.0"
+        _assert_local_files_kept(plugin_dir)
+
+    def test_token_alone_does_not_trigger_a_stash(self, cloned):
+        store, plugin_dir, publish = cloned
+        (plugin_dir / "token.pickle").write_bytes(b"tok")
+
+        publish("1.1.0")
+        assert store.update_plugin(PLUGIN_ID) is True
+
+        assert (plugin_dir / "token.pickle").read_bytes() == b"tok"
+        stashes = subprocess.run(["git", "-C", str(plugin_dir), "stash", "list"],
+                                 capture_output=True, text=True, check=True)
+        assert stashes.stdout.strip() == ""
+
+
+class TestWhatIsKept:
+    @pytest.mark.parametrize("path,expected", [
+        ("token.pickle", True),
+        ("data/session.pickle", True),
+        ("credentials.json", True),
+        ("token.json", True),
+        ("config_secrets.json", True),
+        (".pkce_code_verifier", True),
+        ("manager.py", False),
+        ("config.json", False),
+    ])
+    def test_known_state_files(self, path, expected):
+        assert is_known_state_file(path) is expected
+
+    def test_gitignore_rules(self, tmp_path):
+        old, new = tmp_path / "old", tmp_path / "new"
+        new.mkdir()
+        for rel in ["a.log", "logs/x.txt", "sub/deep/b.log", "keep.log",
+                    "anchored.txt", "sub/anchored.txt", "assets/x/y_backup/z.png",
+                    "manager.py", "shipped.log"]:
+            (old / rel).parent.mkdir(parents=True, exist_ok=True)
+            (old / rel).write_text("x")
+        (new / "shipped.log").write_text("new")
+        (old / ".gitignore").write_text(
+            "# comment\n*.log\n!keep.log\nlogs/\n/anchored.txt\n"
+            "assets/**/*_backup/\n")
+
+        assert local_files_to_keep(old, new) == [
+            "a.log", "anchored.txt", "assets/x/y_backup/z.png",
+            "logs/x.txt", "sub/deep/b.log",
+        ]

test/test_vegas_participation.py

@@ -446,7 +446,7 @@ class TestInstalledPluginsApi:
                     **(manifest_extra or {})}
             api.plugin_catalog.get_all_plugin_info = MagicMock(return_value=[info])
             api.plugin_catalog.get_plugin_directory = MagicMock(return_value=None)
-            api.plugin_store_manager.get_registry_info = MagicMock(return_value=None)
+            api.plugin_store_manager.get_cached_registry_info = MagicMock(return_value=None)
             api.config_manager.load_config = MagicMock(return_value={'demo': config})
             response = api_v3_client.get('/api/v3/plugins/installed')
             assert response.status_code == 200

test/test_vegas_static_mode.py

@@ -219,8 +219,7 @@ class TestCoordinatorStaticPause:
     def _plugin(self):
         plugin = MagicMock()
         plugin.plugin_id = 'clock'
-        # A moment: zero would pause 15 s, as the rotation shows it.
-        plugin.get_display_duration.return_value = 0.01
+        plugin.get_display_duration.return_value = 0
         return plugin
 
     def test_trigger_comes_from_the_pipeline(self):

test/test_vegas_static_pause_duration.py

@@ -1,197 +0,0 @@
-"""A Vegas static pause lasts as long as the rotation shows the plugin.
-
-The pause asked the plugin for get_display_duration() and compared the
-answer with the clock. Several plugins (clock-simple, calendar, countdown)
-return their display_duration setting as it is in config.json, so one saved
-as "20" or null -- the raw config editor, a hand edit -- reached that
-comparison as a string or None. The TypeError went to the pause's broad
-except, which ended the pause: the plugin flashed up and the scroll went on,
-at every one of its turns. inf paused until something interrupted it, and
-NaN, False, 0 or a negative number ended the pause at once.
-
-The pause now reads the answer the way the rotation does since #739, with
-the same helper (base_plugin.finite_seconds): a numeric string counts;
-anything else that is not a finite number, or a raise, gets the rotation's
-30 s; a number at or below zero gets its 15 s.
-"""
-
-import logging
-import os
-import threading
-from types import SimpleNamespace
-from unittest.mock import MagicMock
-
-os.environ.setdefault("EMULATOR", "true")
-
-import pytest
-
-from src.vegas_mode import coordinator
-
-NOT_NUMBERS = [None, '', 'twenty', True, False, float('nan'), float('inf'),
-               'inf', '1e400', [20], {'seconds': 20}]
-NOT_ABOVE_ZERO = [0, -5, '-5', '0']
-NUMBERS = [('20', 20.0), (' 7.5 ', 7.5), (12, 12.0), (12.5, 12.5)]
-
-
-class FakeClock:
-    """time.monotonic/time.sleep for the pause loop: sleeping moves the clock."""
-
-    #: A pause still going after this long never ends (inf did that).
-    LIMIT = 3600.0
-
-    def __init__(self):
-        self.now = 0.0
-
-    def monotonic(self):
-        return self.now
-
-    def sleep(self, seconds):
-        self.now += seconds
-        if self.now > self.LIMIT:
-            raise RuntimeError("the static pause never ended")
-
-
-@pytest.fixture
-def clock(monkeypatch):
-    fake = FakeClock()
-    monkeypatch.setattr(coordinator, 'time', fake)
-    return fake
-
-
-def _plugin(duration, plugin_id='clock-simple'):
-    plugin = MagicMock()
-    plugin.plugin_id = plugin_id
-    plugin.get_display_duration.return_value = duration
-    return plugin
-
-
-def _coord(*plugins):
-    coord = coordinator.VegasModeCoordinator.__new__(coordinator.VegasModeCoordinator)
-    coord.render_pipeline = MagicMock()
-    coord.render_pipeline.get_scroll_position.return_value = 0
-    coord.display_manager = MagicMock()
-    locks = {plugin.plugin_id: threading.Lock() for plugin in plugins}
-    coord.plugin_manager = SimpleNamespace(get_plugin_lock=locks.__getitem__)
-    coord._state_lock = threading.Lock()
-    coord._static_pause_active = False
-    coord._saved_scroll_position = None
-    coord._should_stop = False
-    coord._live_priority_active = False
-    coord._live_priority_check = None
-    coord._interrupt_check = None
-    coord.stats = {'static_pauses': 0}
-    return coord
-
-
-def _pause(coord, plugin, clock):
-    """One static pause: (whether it completed, how long it lasted)."""
-    start = clock.now
-    completed = coord._handle_static_pause(plugin)
-    return completed, clock.now - start
-
-
-class TestPauseLength:
-    @pytest.mark.parametrize('value, seconds', NUMBERS)
-    def test_numbers_and_numeric_strings_are_used(self, clock, value, seconds):
-        plugin = _plugin(value)
-        completed, lasted = _pause(_coord(plugin), plugin, clock)
-        assert completed is True
-        assert lasted == pytest.approx(seconds, abs=0.15)
-
-    @pytest.mark.parametrize('value', NOT_NUMBERS, ids=repr)
-    def test_anything_but_a_finite_number_pauses_for_30s(self, clock, value):
-        plugin = _plugin(value)
-        completed, lasted = _pause(_coord(plugin), plugin, clock)
-        assert completed is True
-        assert lasted == pytest.approx(30.0, abs=0.15)
-        plugin.display.assert_called_once_with(force_clear=True)
-
-    @pytest.mark.parametrize('value', NOT_ABOVE_ZERO, ids=repr)
-    def test_a_number_not_above_zero_pauses_for_15s(self, clock, value):
-        plugin = _plugin(value)
-        completed, lasted = _pause(_coord(plugin), plugin, clock)
-        assert completed is True
-        assert lasted == pytest.approx(15.0, abs=0.15)
-
-    def test_a_raising_get_display_duration_pauses_for_30s(self, clock):
-        plugin = _plugin(None)
-        plugin.get_display_duration.side_effect = KeyError('display_duration')
-        completed, lasted = _pause(_coord(plugin), plugin, clock)
-        assert completed is True
-        assert lasted == pytest.approx(30.0, abs=0.15)
-
-    def test_a_good_value_after_a_bad_one_is_used(self, clock):
-        plugin = _plugin(None)
-        coord = _coord(plugin)
-        assert _pause(coord, plugin, clock)[1] == pytest.approx(30.0, abs=0.15)
-        plugin.get_display_duration.return_value = 45
-        assert _pause(coord, plugin, clock)[1] == pytest.approx(45.0, abs=0.15)
-
-    def test_the_pause_can_still_be_interrupted(self, clock):
-        plugin = _plugin('twenty')
-        coord = _coord(plugin)
-        coord._interrupt_check = lambda: clock.now >= 5
-        completed, lasted = _pause(coord, plugin, clock)
-        assert completed is False
-        assert lasted == pytest.approx(5.0, abs=0.15)
-
-
-class TestWarning:
-    def test_logged_once_per_plugin(self, clock, caplog):
-        clock_plugin = _plugin('twenty')
-        calendar = _plugin(None, plugin_id='calendar')
-        coord = _coord(clock_plugin, calendar)
-        with caplog.at_level(logging.WARNING, logger='src.vegas_mode.coordinator'):
-            for _ in range(3):
-                for plugin in (clock_plugin, calendar):
-                    coord._handle_static_pause(plugin)
-        warnings = [r.getMessage() for r in caplog.records
-                    if 'display duration' in r.getMessage()]
-        assert len(warnings) == 2
-        assert any('clock-simple' in m and "'twenty'" in m for m in warnings)
-        assert any('calendar' in m and 'None' in m for m in warnings)
-
-
-class TestFiniteSeconds:
-    """The shared rule: what counts as a number of seconds."""
-
-    @pytest.mark.parametrize('value, seconds', NUMBERS + [(0, 0.0), ('-5', -5.0)])
-    def test_numbers_and_numeric_strings(self, value, seconds):
-        from src.plugin_system.base_plugin import finite_seconds
-        result = finite_seconds(value)
-        assert result == seconds and isinstance(result, float)
-
-    @pytest.mark.parametrize('value', NOT_NUMBERS + [pytest.param(10 ** 400, id='10**400')],
-                             ids=repr)
-    def test_anything_else_is_none(self, value):
-        from src.plugin_system.base_plugin import finite_seconds
-        assert finite_seconds(value) is None
-
-
-def _rotation_seconds(plugin):
-    """How long the rotation shows ``plugin`` (no dynamic duration, no
-    Rotation & Durations override): the two calls run() makes for a screen.
-    """
-    from src.display_controller import DisplayController
-    dc = object.__new__(DisplayController)
-    dc.config = {}
-    dc.plugin_modes = {'mode': plugin}
-    return dc._resolve_durations(plugin, 'mode', dc._get_display_duration('mode'), False)[1]
-
-
-class TestSameAsTheRotation:
-    """The pause and the rotation share finite_seconds; this pins their
-    fallbacks (30 s, 15 s) to each other too."""
-
-    @pytest.mark.parametrize('value', [value for value, _ in NUMBERS]
-                             + NOT_NUMBERS + NOT_ABOVE_ZERO, ids=repr)
-    def test_the_pause_lasts_as_long_as_the_rotation_shows_it(self, clock, value):
-        plugin = _plugin(value)
-        expected = _rotation_seconds(plugin)
-        assert _pause(_coord(plugin), plugin, clock)[1] == pytest.approx(expected, abs=0.15)
-
-    def test_a_raise_too(self, clock):
-        plugin = _plugin(None)
-        plugin.get_display_duration.side_effect = KeyError('display_duration')
-        expected = _rotation_seconds(plugin)
-        assert _pause(_coord(plugin), plugin, clock)[1] == pytest.approx(expected, abs=0.15)

test/test_web_api.py

@@ -551,7 +551,7 @@ class TestPluginsAPI:
         mock_plugin_catalog.get_all_plugin_info.return_value = [
             {'id': 'weather', 'name': 'Weather Plugin'}
         ]
-        api_v3.plugin_store_manager.get_registry_info.return_value = None
+        api_v3.plugin_store_manager.get_cached_registry_info.return_value = None
 
         response = client.get('/api/v3/plugins/installed')
 
@@ -571,7 +571,7 @@ class TestPluginsAPI:
             {'id': 'weather', 'name': 'Weather', 'version': '1.0.0'}
         ]
         # Registry advertises a newer version than the installed one.
-        api_v3.plugin_store_manager.get_registry_info.return_value = {
+        api_v3.plugin_store_manager.get_cached_registry_info.return_value = {
             'verified': True, 'latest_version': '1.2.0'
         }
 
@@ -592,7 +592,7 @@ class TestPluginsAPI:
         mock_plugin_catalog.get_all_plugin_info.return_value = [
             {'id': 'weather', 'name': 'Weather', 'version': '1.2.0'}
         ]
-        api_v3.plugin_store_manager.get_registry_info.return_value = {
+        api_v3.plugin_store_manager.get_cached_registry_info.return_value = {
             'verified': True, 'latest_version': '1.2.0'
         }
 

test/test_web_plugin_dir_resolution.py

@@ -59,7 +59,7 @@ class TestInstalledList:
         info = {"id": "demo", "name": "Demo", "version": "1.0.0",
                 "description": "stale cached copy", "loaded": False}
         api.plugin_catalog.get_all_plugin_info = MagicMock(return_value=[info])
-        api.plugin_store_manager.get_registry_info = MagicMock(return_value=None)
+        api.plugin_store_manager.get_cached_registry_info = MagicMock(return_value=None)
         api.plugin_store_manager._get_local_git_info = MagicMock(return_value=None)
         api.config_manager.load_config = MagicMock(return_value={})
 

test/web_interface/test_es_modules.py

@@ -43,7 +43,8 @@ def _url(path):
 def test_the_module_directories_hold_modules():
     assert {p.name for p in MODULES} >= {"boot.js", "registry.js", "api.js", "facade.js", "cache.js",
                                          "durations.js", "operation-history.js", "raw-json.js",
-                                         "backup-restore.js"}
+                                         "backup-restore.js", "schedule.js", "general.js",
+                                         "visibility.js", "display.js"}
     for directory in MODULE_DIRS:
         # node needs this to import them in the JS tests; browsers ignore it.
         assert '"type": "module"' in (directory / "package.json").read_text(encoding="utf-8")
@@ -104,6 +105,9 @@ CONVERTED = {
     "operation-history": ("operation_history.html", "/partials/operation-history"),
     "raw-json": ("raw_json.html", "/partials/raw-json"),
     "backup-restore": ("backup_restore.html", "/partials/backup-restore"),
+    "schedule": ("schedule.html", "/partials/schedule"),
+    "general": ("general.html", "/partials/general"),
+    "display": ("display.html", "/partials/display"),
 }
 
 # Old window.* names that moved into a page module. Each stays as a
@@ -114,6 +118,9 @@ ALIASES = {
                  "saveMainConfig", "saveSecretsConfig"],
     "backup-restore": ["exportBackup", "loadBackupList", "validateRestoreFile",
                        "clearRestore", "runRestore"],
+    "schedule": ["handleScheduleResponse", "handleDimScheduleResponse"],
+    "general": ["webLogin"],
+    "display": ["updateSyncUI"],
 }
 
 
@@ -155,12 +162,15 @@ def test_moved_globals_stay_as_aliases(name):
         assert f"'{global_name}'" in boot, f"boot.js does not alias {global_name}"
         assert re.search(rf"^export (?:function|const) {global_name}\b", module, re.M), (
             f"pages/{name}.js does not export {global_name}")
-    # No template defines them any more.
+    # No template defines them any more, or calls them (an inline handler
+    # would reach the page only through the deprecated alias).
     for partial in PARTIALS.glob("*.html"):
         text = partial.read_text(encoding="utf-8")
         for global_name in ALIASES[name]:
             assert f"window.{global_name} =" not in text, partial.name
             assert f"function {global_name}(" not in text, partial.name
+            assert not re.search(rf"\b{global_name}\b", text), (
+                f"{partial.name} still names {global_name}")
 
 
 def test_every_registered_page_has_its_module_and_partial():
@@ -180,3 +190,32 @@ def test_converted_partials_carry_no_inline_script():
         if "data-page=" in text:
             assert "<script" not in text.lower(), (
                 f"{partial.name} is a page module now; its code belongs in js/pages/")
+
+
+def test_the_schedule_page_reads_its_config_back_intact():
+    """schedule.html hands both saved schedules to pages/schedule.js as JSON in
+    single-quoted data attributes; a value with quotes or markup must neither
+    end the attribute nor change on the way."""
+    from html.parser import HTMLParser
+    import json
+    import web_interface.app as web_app
+    from flask import render_template
+
+    hostile = {"mode": "per-day", "start_time": "07:00", "note": "it's a \"<b>\" & '</div>"}
+
+    class Root(HTMLParser):
+        attrs = None
+
+        def handle_starttag(self, tag, attrs):
+            if dict(attrs).get("data-page") == "schedule":
+                self.attrs = dict(attrs)
+
+    with web_app.app.test_request_context():
+        html = render_template("v3/partials/schedule.html", schedule_config=hostile,
+                               dim_schedule_config=None, normal_brightness=90)
+    parser = Root()
+    parser.feed(html)
+    assert parser.attrs is not None
+    assert json.loads(parser.attrs["data-schedule-config"]) == hostile
+    # A missing dim schedule arrives as null; the page treats that as {}.
+    assert json.loads(parser.attrs["data-dim-schedule-config"]) is None

test/web_interface/test_starlark_pixlet_routes.py

@@ -26,13 +26,44 @@ import pytest
 
 
 @pytest.fixture
-def client():
+def client(monkeypatch):
+    from web_interface import app as web_app
     from web_interface.app import app
+    # The captive-portal before_request hook shells out to systemctl/nmcli
+    # whenever its 30s cache is cold, so on a Linux host whether a request
+    # here runs subprocess depended on how long ago the previous one was --
+    # and several tests below stub subprocess. Pin it: no test in this file
+    # is about AP mode.
+    monkeypatch.setattr(web_app, 'is_ap_mode_active', lambda: False)
+    # GET /plugins/installed looks up each plugin's registry entry, and on a
+    # cold cache that fetches plugins.json from GitHub -- so without a
+    # connection those tests sat in the HTTP retry loop. No test in this
+    # file is about the registry.
+    monkeypatch.setattr(web_app.plugin_store_manager, 'fetch_registry',
+                        lambda *args, **kwargs: {'plugins': []})
     app.config['TESTING'] = True
     with app.test_client() as c:
         yield c
 
 
+@pytest.fixture(autouse=True)
+def starlark_apps_dir(tmp_path, monkeypatch):
+    """Point every Starlark storage path at tmp_path for every test.
+
+    The manifest, its directory and the lock file are three separate module
+    constants. Fixtures that redirected the first two but not the lock left
+    the lock pointing at the repo, and on Linux (where the lock is taken)
+    each test created starlark-apps/manifest.json.lock in the checkout. The
+    directory is not created here; tests that need it make it.
+    """
+    from web_interface.blueprints import api_v3 as module
+    apps_dir = tmp_path / "starlark-apps"
+    monkeypatch.setattr(module, '_STARLARK_APPS_DIR', apps_dir)
+    monkeypatch.setattr(module, '_STARLARK_MANIFEST_FILE', apps_dir / 'manifest.json')
+    monkeypatch.setattr(module, '_STARLARK_MANIFEST_LOCK_FILE', apps_dir / 'manifest.json.lock')
+    return apps_dir
+
+
 class TestRoutesAreRegistered:
     """The failure was a missing route, so check the URL map directly.
 
@@ -391,13 +422,9 @@ class TestTheManifestSurvivesConcurrentWriters:
     """
 
     @pytest.fixture
-    def starlark_dir(self, tmp_path, monkeypatch):
-        from web_interface.blueprints import api_v3 as module
-        apps_dir = tmp_path / "starlark-apps"
-        apps_dir.mkdir()
-        monkeypatch.setattr(module, '_STARLARK_APPS_DIR', apps_dir)
-        monkeypatch.setattr(module, '_STARLARK_MANIFEST_FILE', apps_dir / 'manifest.json')
-        return apps_dir
+    def starlark_dir(self, starlark_apps_dir):
+        starlark_apps_dir.mkdir()
+        return starlark_apps_dir
 
     def test_each_writer_gets_its_own_temp_file(self, starlark_dir):
         from web_interface.blueprints import api_v3 as module
@@ -553,13 +580,9 @@ class TestTheManifestStaysRelocatable:
     """
 
     @pytest.fixture
-    def starlark_dir(self, tmp_path, monkeypatch):
-        from web_interface.blueprints import api_v3 as module
-        apps_dir = tmp_path / "starlark-apps"
-        apps_dir.mkdir()
-        monkeypatch.setattr(module, '_STARLARK_APPS_DIR', apps_dir)
-        monkeypatch.setattr(module, '_STARLARK_MANIFEST_FILE', apps_dir / 'manifest.json')
-        return apps_dir
+    def starlark_dir(self, starlark_apps_dir):
+        starlark_apps_dir.mkdir()
+        return starlark_apps_dir
 
     def _install(self, tmp_path):
         from web_interface.blueprints import api_v3 as module
@@ -599,13 +622,10 @@ class TestManifestLockPreventsLostUpdates:
     """
 
     @pytest.fixture
-    def starlark_dir(self, tmp_path, monkeypatch):
+    def starlark_dir(self, starlark_apps_dir):
         from web_interface.blueprints import api_v3 as module
-        apps_dir = tmp_path / "starlark-apps"
+        apps_dir = starlark_apps_dir
         apps_dir.mkdir()
-        monkeypatch.setattr(module, '_STARLARK_APPS_DIR', apps_dir)
-        monkeypatch.setattr(module, '_STARLARK_MANIFEST_FILE', apps_dir / 'manifest.json')
-        monkeypatch.setattr(module, '_STARLARK_MANIFEST_LOCK_FILE', apps_dir / 'manifest.json.lock')
         module._write_starlark_manifest({'apps': {}})
         return apps_dir
 
@@ -693,12 +713,10 @@ class TestConfigAndManifestStayInSync:
     """
 
     @pytest.fixture
-    def app_dir(self, tmp_path, monkeypatch):
+    def app_dir(self, starlark_apps_dir):
         from web_interface.blueprints import api_v3 as module
-        apps_dir = tmp_path / "starlark-apps"
+        apps_dir = starlark_apps_dir
         apps_dir.mkdir()
-        monkeypatch.setattr(module, '_STARLARK_APPS_DIR', apps_dir)
-        monkeypatch.setattr(module, '_STARLARK_MANIFEST_FILE', apps_dir / 'manifest.json')
         one_app_dir = apps_dir / 'demo'
         one_app_dir.mkdir()
         module._write_starlark_manifest({'apps': {'demo': {'name': 'Demo', 'enabled': True}}})
@@ -1042,13 +1060,18 @@ class TestTheStoreUsesTheTokenTheUserConfigured:
     /plugins/store/github-status reported `authenticated: true` with a
     rate_limit of 5000 while /starlark/repository/browse reported a limit of
     60 -- the store going blank was that 60 running out.
+
+    The managers are attributes web_interface/app.py hangs on the blueprint
+    when it is imported, so they exist only once some earlier test has
+    imported the app. Every patch here passes create=True: these tests must
+    not depend on which test ran before them.
     """
 
     def test_the_store_managers_token_is_used(self):
         from web_interface.blueprints import api_v3 as mod
 
         with patch.object(mod.api_v3, 'plugin_store_manager',
-                          MagicMock(github_token='ghp_configured')):
+                          MagicMock(github_token='ghp_configured'), create=True):
             assert mod._starlark_github_token() == 'ghp_configured'
 
     def test_a_hand_edited_config_key_still_works(self):
@@ -1057,8 +1080,8 @@ class TestTheStoreUsesTheTokenTheUserConfigured:
         cfg = MagicMock()
         cfg.load_config.return_value = {'github_token': 'ghp_by_hand'}
         with patch.object(mod.api_v3, 'plugin_store_manager',
-                          MagicMock(github_token=None)), \
-             patch.object(mod.api_v3, 'config_manager', cfg):
+                          MagicMock(github_token=None), create=True), \
+             patch.object(mod.api_v3, 'config_manager', cfg, create=True):
             assert mod._starlark_github_token() == 'ghp_by_hand'
 
     def test_no_token_anywhere_is_not_an_error(self):
@@ -1067,8 +1090,8 @@ class TestTheStoreUsesTheTokenTheUserConfigured:
         cfg = MagicMock()
         cfg.load_config.return_value = {}
         with patch.object(mod.api_v3, 'plugin_store_manager',
-                          MagicMock(github_token=None)), \
-             patch.object(mod.api_v3, 'config_manager', cfg):
+                          MagicMock(github_token=None), create=True), \
+             patch.object(mod.api_v3, 'config_manager', cfg, create=True):
             assert mod._starlark_github_token() is None
 
     def test_an_unreadable_config_does_not_take_the_store_down(self):
@@ -1077,8 +1100,8 @@ class TestTheStoreUsesTheTokenTheUserConfigured:
         cfg = MagicMock()
         cfg.load_config.side_effect = OSError("config.json is unreadable")
         with patch.object(mod.api_v3, 'plugin_store_manager',
-                          MagicMock(github_token=None)), \
-             patch.object(mod.api_v3, 'config_manager', cfg):
+                          MagicMock(github_token=None), create=True), \
+             patch.object(mod.api_v3, 'config_manager', cfg, create=True):
             assert mod._starlark_github_token() is None
 
     def test_browse_hands_the_token_to_the_repository(self, client):
@@ -1092,7 +1115,7 @@ class TestTheStoreUsesTheTokenTheUserConfigured:
         repo.return_value.get_rate_limit_info.return_value = {'remaining': 4999}
 
         with patch.object(mod.api_v3, 'plugin_store_manager',
-                          MagicMock(github_token='ghp_configured')), \
+                          MagicMock(github_token='ghp_configured'), create=True), \
              patch('web_interface.blueprints.api_v3._get_tronbyte_repository_class',
                    return_value=repo):
             client.get('/api/v3/starlark/repository/browse')
@@ -1136,12 +1159,23 @@ class TestPixletEditorHostDefaultsButDoesNotOverride:
                 captured['env'] = env
             return FakeProcess()
 
+        # Swap the route module's own ``subprocess`` binding, not the shared
+        # ``subprocess.Popen``: patching the attribute on the real module is
+        # process-wide, and the app's before_request hook (the captive-portal
+        # check) runs ``subprocess.run`` -- ``with Popen(...)`` -- whenever its
+        # 30s AP-mode cache is cold on a host with systemctl. On the Linux CI
+        # runner that handed it this FakeProcess and 500'd the request, but
+        # only when the previous request was more than 30s earlier.
+        fake_subprocess = types.ModuleType('subprocess')
+        fake_subprocess.__dict__.update(mod.subprocess.__dict__)
+        fake_subprocess.Popen = fake_popen
+
         with patch.object(mod, '_validate_starlark_app_path',
                           return_value=(app_dir, None)), \
              patch.object(mod, '_PIXLET_EDITOR_SCRIPT', script), \
              patch.object(mod, '_PIXLET_EDITOR_STATE', state_file), \
              patch.object(mod, '_find_pixlet_binary', return_value='/usr/bin/pixlet'), \
-             patch.object(mod.subprocess, 'Popen', side_effect=fake_popen), \
+             patch.object(mod, 'subprocess', fake_subprocess), \
              patch.dict(os.environ):
             if operator_host is None:
                 os.environ.pop('PIXLET_EDITOR_HOST', None)
@@ -1171,15 +1205,13 @@ class TestStandaloneRenderUsesTheDeviceLocation:
     SCHEMA = {"schema": [{"typeOf": "location", "id": "location"}]}
 
     @pytest.fixture
-    def app_dir(self, tmp_path, monkeypatch):
+    def app_dir(self, starlark_apps_dir, monkeypatch):
         from web_interface.blueprints import api_v3 as module
-        apps_dir = tmp_path / "starlark-apps"
+        apps_dir = starlark_apps_dir
         app_dir = apps_dir / "weather"
         app_dir.mkdir(parents=True)
         (app_dir / "weather.star").write_text("# app")
         (app_dir / "schema.json").write_text(json.dumps(self.SCHEMA))
-        monkeypatch.setattr(module, '_STARLARK_APPS_DIR', apps_dir)
-        monkeypatch.setattr(module, '_STARLARK_MANIFEST_FILE', apps_dir / 'manifest.json')
         (apps_dir / 'manifest.json').write_text(json.dumps(
             {'apps': {'weather': {'star_file': 'weather.star'}}}))
         config_manager = MagicMock()

test/web_interface/test_web_process_runs_no_plugin_code.py

@@ -128,6 +128,7 @@ class Web:
         store = api.plugin_store_manager
         store.plugins_dir = str(self.plugins_dir)
         store.get_registry_info.return_value = None
+        store.get_cached_registry_info.return_value = None
         store.get_plugin_info.return_value = None
         store._get_local_git_info.return_value = None
         store.install_plugin.return_value = True
@@ -221,7 +222,9 @@ class TestTheWebProcessNeverRunsAPlugin:
     def test_saving_its_section_through_the_main_config(self, web):
         body = web.post("/api/v3/config/main", {PLUGIN_ID: {"message": "via main"}})
         assert web.stored()["message"] == "via main"
-        assert body["restart_required"] is True
+        # The display's config watcher hands the section to the running
+        # plugin (on_config_change), as for /plugins/config: no restart.
+        assert body["restart_required"] is False
         assert web.ran() == []
 
     def test_resetting_its_config(self, web):

web_interface/blueprints/api_v3/config.py

@@ -17,6 +17,8 @@ from src.pi5_matrix_support import is_raspberry_pi_5
 from web_interface.cache import invalidate_cache
 from web_interface.auth import SECTION as _WEB_AUTH_SECTION, strip_auth_section
 import web_interface.blueprints.api_v3 as _pkg
+import copy
+from typing import Any, Dict, Iterable, Tuple
 
 # Read through the module rather than bound by value: tests patch these
 # as module attributes, and a value binding would not see the patch.
@@ -33,6 +35,50 @@ FORM_SECTION_FIELD = '__form_section'
 GENERAL_FIELDS = ('timezone', 'city', 'state', 'country', 'web_display_autostart',
                   'plugins_directory', 'auto_update_enabled', 'auto_update_channel')
 
+#: Settings in config.json the running display applies without a restart,
+#: as key paths (a path covers everything under it). Brightness goes over the
+#: control socket (brightness.set) and the config watcher's refresh
+#: (DisplayController._refresh_config_cache); the per-mode durations are read
+#: from the live config each time a mode starts (_get_display_duration).
+#: Plugin sections are live as well (each plugin's on_config_change), and
+#: save_main_config adds the ones a request saves.
+LIVE_CONFIG_PATHS: Tuple[Tuple[str, ...], ...] = (
+    ('display', 'hardware', 'brightness'),
+    ('display', 'display_durations'),
+)
+
+
+_MISSING = object()
+
+
+def _config_leaves(config: Any, prefix: Tuple[str, ...] = ()) -> Dict[Tuple[str, ...], Any]:
+    """Every non-dict value in ``config``, by key path. An empty dict has none,
+    so a section created empty on the way to a field is not a change."""
+    if not isinstance(config, dict):
+        return {prefix: config}
+    leaves: Dict[Tuple[str, ...], Any] = {}
+    for key, value in config.items():
+        leaves.update(_config_leaves(value, prefix + (str(key),)))
+    return leaves
+
+
+def restart_needed(before: Dict[str, Any], after: Dict[str, Any],
+                   live_paths: Iterable[Tuple[str, ...]] = LIVE_CONFIG_PATHS) -> bool:
+    """Does going from config ``before`` to ``after`` need a display restart?
+
+    True when anything changed outside ``live_paths``. A save that changes
+    only live settings, or nothing at all, does not.
+    """
+    live = tuple(live_paths)
+    old, new = _config_leaves(before), _config_leaves(after)
+    for path in set(old) | set(new):
+        if old.get(path, _MISSING) == new.get(path, _MISSING):
+            continue
+        if not any(path[:len(prefix)] == prefix for prefix in live):
+            return True
+    return False
+
+
 #: Top-level fields save_main_config stores somewhere of its own (location,
 #: plugin_system, ...), never as a config key of the same name.
 _MAPPED_TOP_LEVEL_FIELDS = GENERAL_FIELDS + (
@@ -72,6 +118,22 @@ def _day_setting(data, day, flat_key, nested_key):
     return False, None
 
 
+def _disabled_day_times(data, day, start_key, end_key):
+    """The times posted for a day that is off, the valid ones.
+
+    Nothing reads them while the day is off, but the schedule picker posts
+    them and GET returns them, so keeping them means turning the day back on
+    finds what was there. An invalid one is dropped rather than refused, for
+    the same reason.
+    """
+    times = {}
+    for field, key in (('start_time', start_key), ('end_time', end_key)):
+        value = _day_setting(data, day, key, field)[1]
+        if value and _validate_time_format(value)[0]:
+            times[field] = value
+    return times
+
+
 @api_v3.route('/config/main', methods=['GET'])
 def get_main_config():
     """Get main configuration, with credentials redacted."""
@@ -257,11 +319,16 @@ def save_schedule_config():
 
                     day_config['start_time'] = start_time
                     day_config['end_time'] = end_time
+                else:
+                    day_config.update(_disabled_day_times(data, day, start_key, end_key))
 
                 schedule_config['days'][day] = day_config
 
-            # Validate that at least one day is enabled in per-day mode
-            if enabled_days_count == 0:
+            # An enabled per-day schedule needs a day to be on. A disabled
+            # one does not: every day off with the schedule off is what
+            # config.template.json ships, so refusing it meant a fresh
+            # install could not post back the schedule GET returned.
+            if enabled_days_count == 0 and enabled_value:
                 return error_response(
                     ErrorCode.VALIDATION_ERROR,
                     "At least one day must be enabled in per-day schedule mode",
@@ -465,11 +532,13 @@ def save_dim_schedule_config():
 
                     day_config['start_time'] = start_time
                     day_config['end_time'] = end_time
+                else:
+                    day_config.update(_disabled_day_times(data, day, start_key, end_key))
 
                 dim_schedule_config['days'][day] = day_config
 
-            # Validate that at least one day is enabled in per-day mode
-            if enabled_days_count == 0:
+            # As for the on/off schedule: only an enabled one needs a day on.
+            if enabled_days_count == 0 and enabled_value:
                 return error_response(
                     ErrorCode.VALIDATION_ERROR,
                     "At least one day must be enabled in per-day dim schedule mode",
@@ -557,6 +626,8 @@ def save_main_config():
 
         # Merge with existing config (similar to original implementation)
         current_config = api_v3.config_manager.load_config()
+        # What was stored, to tell which settings this save changed.
+        stored_config = copy.deepcopy(current_config)
         was_auto_update_enabled = bool((current_config.get('auto_update') or {}).get('enabled'))
 
         is_general_update = any(k in data for k in GENERAL_FIELDS)
@@ -1194,13 +1265,15 @@ def save_main_config():
                 message = f'{message}. {note}'
         except Exception:
             logger.warning("Automatic update setup could not be started", exc_info=True)
-        # Display hardware, rotation/durations and general settings take
-        # effect after a display restart; the UI shows its restart banner on
-        # this flag.
-        extra = {'restart_required': True}
-        # Brightness is the exception: the display applies a saved one
-        # without a restart. Over the control socket it lands at once,
-        # instead of when the config watcher next looks (up to ~2 s).
+        # Display hardware, rotation order and general settings take effect
+        # after a display restart; the UI shows its restart banner on this
+        # flag. Brightness, mode durations and plugin settings are applied by
+        # the running display (LIVE_CONFIG_PATHS), so a save that changed
+        # only those -- or nothing -- does not ask for one.
+        live_paths = LIVE_CONFIG_PATHS + tuple((plugin_id,) for plugin_id in plugin_keys_to_remove)
+        extra = {'restart_required': restart_needed(stored_config, current_config, live_paths)}
+        # Over the control socket a saved brightness lands at once, instead
+        # of when the config watcher next looks (up to ~2 s).
         if 'brightness' in data:
             saved = (current_config.get('display', {}).get('hardware', {}) or {}).get('brightness')
             if isinstance(saved, int) and not isinstance(saved, bool):

web_interface/blueprints/api_v3/display.py

@@ -33,16 +33,28 @@ def _cache_manager():
 
 
 
+class _NotDelivered(Exception):
+    """The display took an on-demand request over the socket and did not
+    accept it (``busy``, ``invalid_args``, ...) or did not answer in time."""
+
+    def __init__(self, reason):
+        super().__init__(reason)
+        self.reason = reason
+
+
 def _deliver_on_demand(payload):
     """Hand an on-demand request to the display: control socket, else mailbox.
 
     The socket (src/ipc) answers with an acknowledgement as soon as the
-    display has the command queued for its render thread. Any failure -- no
-    socket (the display is stopped or predates it), a timeout, a refusal --
-    writes the file mailbox instead, exactly as before the socket existed;
-    the display reads it within ON_DEMAND_POLL_INTERVAL. Both carry the same
-    request_id, so a request that reached the display both ways (a reply
-    that timed out after the command was queued) is still processed once.
+    display has the command queued for its render thread. The file mailbox
+    is written only when the socket could not carry the request at all
+    (``control_client.should_fall_back``): no socket (the display is stopped
+    or predates it), a refused connection, or a display too old to know the
+    command. The display reads it within its mailbox poll interval.
+
+    A display that had the request and refused it, or did not answer in
+    time, raises :class:`_NotDelivered`: a mailbox copy would be refused
+    the same way, or hide a stuck display behind a "success".
 
     Returns ``(transport, socket_error)``: ``'socket'`` and None, or
     ``'mailbox'`` and the socket failure's reason code.
@@ -57,6 +69,10 @@ def _deliver_on_demand(payload):
         return 'socket', None
     except control_client.ControlError as e:
         reason = _socket_reason_code(e.reason)
+        if not control_client.should_fall_back(e):
+            logger.warning("The display did not accept on-demand %s %s (%s)",
+                           payload['action'], payload['request_id'], e)
+            raise _NotDelivered(reason) from None
         if reason in _QUIET_SOCKET_REASONS:
             logger.debug("On-demand %s via the mailbox: %s", payload['action'], e)
         else:
@@ -69,6 +85,17 @@ def _deliver_on_demand(payload):
     return 'mailbox', reason
 
 
+def _not_delivered_response(request_id, action, reason):
+    """The answer when the display had the request and did not accept it."""
+    status = 400 if reason == 'invalid_args' else 503
+    return jsonify({
+        'status': 'error',
+        'message': (f'The display service did not accept the on-demand {action} '
+                    f'request ({reason})'),
+        'data': {'request_id': request_id, 'transport': 'socket', 'socket_error': reason},
+    }), status
+
+
 def _withdraw_on_demand(request_id):
     """Take a start request the route has refused back out of the mailbox.
 
@@ -277,7 +304,10 @@ def start_on_demand_display():
         'pinned': pinned,
         'timestamp': _pkg.time.time()
     }
-    transport, socket_error = _deliver_on_demand(request_payload)
+    try:
+        transport, socket_error = _deliver_on_demand(request_payload)
+    except _NotDelivered as e:
+        return _not_delivered_response(request_id, 'start', e.reason)
 
     # A socket acknowledgement is the display itself answering: it is
     # running and has the request queued, whatever systemd says (a display
@@ -312,9 +342,10 @@ def start_on_demand_display():
     # MQTT on-demand command, which posts here with the default -- cold-
     # restarted the display process: every plugin reloaded and the panel was
     # blank for seconds. The restart bought nothing. The running process
-    # reads this mailbox every ON_DEMAND_POLL_INTERVAL (0.25s), from its
-    # dwell sleep, its render loops and Vegas's interrupt check as well as
-    # the main loop, and a restarted one got the request the same way: the
+    # looks at this mailbox at least once a second, from its dwell sleep,
+    # its render loops and Vegas's interrupt check as well as the main loop
+    # (DisplayController._mailbox_poll_interval), and a restarted one got
+    # the request the same way: the
     # startup path only restores a session the display itself saved
     # (display_on_demand_config), so it loaded nothing it would not have had.
     service_result = None
@@ -365,7 +396,14 @@ def stop_on_demand_display():
         'action': 'stop',
         'timestamp': _pkg.time.time()
     }
-    transport, socket_error = _deliver_on_demand(request_payload)
+    try:
+        transport, socket_error = _deliver_on_demand(request_payload)
+    except _NotDelivered as e:
+        if not stop_service:
+            return _not_delivered_response(request_id, 'stop', e.reason)
+        # Stopping the service ends on-demand too, whatever the display did
+        # with the request.
+        transport, socket_error = 'socket', e.reason
 
     service_result = None
     if stop_service:
@@ -386,15 +424,22 @@ def get_current_display_status():
     Read from the display's state stream over the control socket when it is
     available (``source: "socket"``). Otherwise from what the display
     publishes to the shared cache (display_controller._publish_current_mode_state)
-    when the active mode changes (``source: "cache"``).
+    when the active mode changes (``source: "cache"``). Unknown (every field
+    None) when the socket and the heartbeat both say the display is gone
+    (display_state.display_gone).
     """
-    state = display_state.current_status(display_state.read_state())
+    snapshot = display_state.read_state()
+    state = display_state.current_status(snapshot)
     source = 'socket'
     if state is None:
         source = 'cache'
-        cache = _cache_manager()
-        # memory_ttl=0: written by the display service; see get_on_demand_status.
-        state = cache.get('display_current_state', max_age=120, memory_ttl=0)
+        # A stopped display leaves its last answer in the cache, where it
+        # read as on (is_display_active: true) for the 120 s max_age. With
+        # no socket and no live heartbeat there is no display behind it.
+        if not display_state.display_gone(snapshot):
+            cache = _cache_manager()
+            # memory_ttl=0: written by the display service; see get_on_demand_status.
+            state = cache.get('display_current_state', max_age=120, memory_ttl=0)
     if state is None:
         state = {
             'mode': None,

web_interface/blueprints/api_v3/misc.py

@@ -102,6 +102,7 @@ def get_health():
         # the only signal, as it always was.
         # The display reports the same beat's age over the control socket's
         # state stream, measured in memory; the file is the fallback.
+        snapshot = None
         try:
             snapshot = display_state.read_state()
             if snapshot is not None:
@@ -132,6 +133,26 @@ def get_health():
                 'error': 'see logs for details'
             }
 
+        # A stopped display service. The heartbeat's absence alone says
+        # nothing (the dev server, the emulator and Windows write none), so
+        # the overall status stayed "healthy" with the display down until the
+        # last preview frame it left aged past 60 s (hardware: stale). Together
+        # the three signals are definite: systemd says the service is not
+        # active, the control socket does not answer, and there is no live
+        # heartbeat (display_state.display_gone, which is never true where
+        # the platform has no socket or it is switched off).
+        try:
+            if (not display_service_status.get('active')
+                    and display_state.display_gone(snapshot)):
+                health_status['checks']['display_loop'] = {
+                    'status': 'stopped',
+                    'note': 'The display service is not running',
+                    'source': 'service',
+                }
+        except Exception:
+            logger.warning("Health check could not tell whether the display is stopped",
+                           exc_info=True)
+
         # Check hardware connectivity (if display manager available)
         try:
             snapshot_path = display_preview.SNAPSHOT_PATH
@@ -353,6 +374,23 @@ def _read_errors():
     return snapshot, clear_request
 
 
+def _send_error_clear(request_id, cutoff):
+    """``errors.clear`` over the control socket: the display's answer, or None
+    when the socket could not carry it (no socket, or a display older than
+    the command) and the clear goes to the mailbox instead. A display that
+    took the request and failed raises ControlError (no second copy)."""
+    client = _pkg.control_client
+    try:
+        return client.errors_clear(request_id, cutoff)
+    except client.ControlError as e:
+        if not client.should_fall_back(e):
+            raise
+        _pkg._log_socket_failure('errors.clear', e, _pkg._socket_reason_code(e.reason))
+    except Exception:  # never let the socket path break the route
+        logger.exception("Control socket client failed clearing errors; using the mailbox")
+    return None
+
+
 @api_v3.route('/errors/summary', methods=['GET'])
 def get_error_summary():
     """
@@ -450,7 +488,17 @@ def clear_old_errors():
         now = _pkg.time.time()
         cutoff = now if clear_all else now - max_age_hours * 3600
         try:
-            result = _errors.request_error_clear(_errors_cache(), cutoff)
+            result = _errors.request_error_clear(_errors_cache(), cutoff,
+                                                 send=_send_error_clear)
+        except _pkg.control_client.ControlError as e:
+            reason = _pkg._socket_reason_code(e.reason)
+            logger.warning("The display did not apply the error clear: %s", e)
+            return error_response(
+                error_code=ErrorCode.SYSTEM_ERROR,
+                message="The display service did not apply the clear",
+                context={'socket_error': reason},
+                status_code=503
+            )
         except OSError as e:
             logger.error("Could not record an error clear request: %s", e)
             return error_response(
@@ -460,11 +508,12 @@ def clear_old_errors():
             )
 
         scope = "all errors" if clear_all else f"errors older than {max_age_hours} hours"
-        return success_response(
-            data=result,
-            message=(f"Clear of {scope} requested; the display service applies it "
-                     f"within about {int(_errors.SNAPSHOT_TICK_INTERVAL)} seconds")
-        )
+        if result.get('applied'):
+            message = f"Cleared {scope}"
+        else:
+            message = (f"Clear of {scope} requested; the display service applies it "
+                       f"within about {int(_errors.SNAPSHOT_TICK_INTERVAL)} seconds")
+        return success_response(data=result, message=message)
     except Exception as e:
         logger.error(f"Error clearing old errors: {e}", exc_info=True)
         return error_response(

web_interface/blueprints/api_v3/plugin_store.py

@@ -530,13 +530,11 @@ def install_plugin():
                     )
 
                 branch_msg = f" (branch: {branch})" if branch else ""
-                # plugin_id: the id to enable it by, and the id its config
-                # section is under (see _installed_plugin_id).
-                installed_id = _installed_plugin_id(plugin_id)
+                # plugin_id: the id to enable it by (see _installed_plugin_id).
                 return {'success': True,
                         'message': f'Plugin {plugin_id} installed successfully{branch_msg}',
-                        'plugin_id': installed_id,
-                        **_store_restart_fields('install', _plugin_enabled_in_config(installed_id))}
+                        'plugin_id': _installed_plugin_id(plugin_id),
+                        **_store_restart_fields('install', _plugin_enabled_in_config(plugin_id))}
             else:
                 error_msg = f'Failed to install plugin {plugin_id}'
                 if branch:
@@ -590,11 +588,10 @@ def install_plugin():
                 )
 
             branch_msg = f" (branch: {branch})" if branch else ""
-            installed_id = _installed_plugin_id(plugin_id)
             return success_response(
                 message=f'Plugin installed successfully{branch_msg}',
-                extra={'plugin_id': installed_id,
-                       **_store_restart_fields('install', _plugin_enabled_in_config(installed_id))})
+                extra={'plugin_id': _installed_plugin_id(plugin_id),
+                       **_store_restart_fields('install', _plugin_enabled_in_config(plugin_id))})
         else:
             error_msg = f'Failed to install plugin {plugin_id}'
             if branch:

web_interface/blueprints/api_v3/plugins.py

@@ -106,8 +106,13 @@ def get_installed_plugins():
             plugin_config = {}
         enabled = bool(plugin_config.get('enabled', False))
 
-        # Verified + latest published version from registry (no network call)
-        store_info = api_v3.plugin_store_manager.get_registry_info(plugin_id)
+        # Verified + latest published version from the registry copy already
+        # in memory. Never a fetch: on a cold cache get_registry_info would
+        # download plugins.json, and offline wait out its timeout and retries
+        # for every plugin. With no copy yet these are absent (no update or
+        # verified badge) and a background refresh fills them in for a
+        # later load.
+        store_info = api_v3.plugin_store_manager.get_cached_registry_info(plugin_id)
         verified = store_info.get('verified', False) if store_info else False
         latest_version = store_info.get('latest_version', '') if store_info else ''
         installed_version = plugin_info.get('version', '')

web_interface/display_state.py

@@ -133,6 +133,39 @@ def on_demand_state(snapshot: Optional[Dict[str, Any]],
     return state
 
 
+def display_gone(snapshot: Optional[Dict[str, Any]]) -> bool:
+    """Is there positively no display behind a fallback to the cache?
+
+    True only when the socket should be there (this platform has one and it
+    is not switched off) but gave no ``snapshot``, and the render loop's
+    heartbeat file says nothing is running either: it is absent (systemd
+    removes its directory when the service stops), stale, or written by a
+    process that no longer exists -- #726's rules for the runtime snapshot.
+    Then what the display last left in the cache is a dead process's answer.
+
+    False whenever the answer is in doubt: a snapshot came in, the socket is
+    off or unsupported (Windows, the test suite, a deliberate ``off``), or a
+    live heartbeat says the display is running without a socket (an older
+    display). Those read the cache exactly as before.
+    """
+    if snapshot is not None:
+        return False
+    if not socket_supported() or not client_socket_paths():
+        return False
+    from src import display_watchdog
+    from src.plugin_system.plugin_runtime import process_exists
+    heartbeat = display_watchdog.read_heartbeat(display_watchdog.HEARTBEAT_PATH)
+    if heartbeat is None:
+        return True
+    age = display_watchdog.heartbeat_age(heartbeat)
+    if age is None or age >= display_watchdog.HEARTBEAT_STALE_SECONDS:
+        return True
+    pid = heartbeat.get('pid')
+    if isinstance(pid, int) and not isinstance(pid, bool) and process_exists(pid) is False:
+        return True
+    return False
+
+
 def loop_heartbeat_age(snapshot: Optional[Dict[str, Any]]) -> Optional[float]:
     """The render loop's heartbeat age now; None when the display has no
     beat to report yet (or there is no snapshot)."""
@@ -141,5 +174,5 @@ def loop_heartbeat_age(snapshot: Optional[Dict[str, Any]]) -> Optional[float]:
     return control_client.snapshot_loop_age(snapshot)
 
 
-__all__ = ['current_status', 'loop_heartbeat_age', 'on_demand_state', 'read_state',
-           'stop_subscription']
+__all__ = ['current_status', 'display_gone', 'loop_heartbeat_age', 'on_demand_state',
+           'read_state', 'stop_subscription']