Merge origin/main

# Conflicts:
#	CHANGELOG.md

CHANGELOG.md

@@ -67,6 +67,34 @@ to for one release are gone.
   interface can no longer start or stop on-demand sessions or clear errors
   on a running display (the mailbox used to carry them).
 
+### 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
@@ -242,6 +270,20 @@ Internal; no behaviour change. Stage 3 of `docs/RUN_LOOP_REDESIGN.md`.
   (`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
 
@@ -716,6 +758,16 @@ 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 the release that ships it, and deletes its copy then.
 
 ### Tooling