fix(calendar): redact script diagnostics, and page the calendar list

Three findings from CodeRabbit, all valid.

Raw subprocess output was being returned to the client -- the script's
stderr on one path, and its own error payload on another. CodeQL flagged
the same line. That script handles OAuth client secrets and interpolates
exceptions into its messages, so either could carry a secret or a path.
Both now go to the log unredacted, where they are worth having in full,
and reach the client through a redactor.

That redactor already existed inside describe_exception, which only
takes exceptions. Split out as redact_text: an exception is not the only
thing worth returning, and a subprocess's stderr is just as capable of
quoting a token.

calendarList.list returns 100 entries per page by default, caps at 250,
and hands back a nextPageToken when there are more. Reading one page
would have hidden calendars from the picker with nothing to say the list
was cut short. It now pages, asking for 250 at a time, bounded at ten
pages so a malformed token cannot spin.

And a test helper was a lambda where ruff wants a def.

The five new tests fail against the previous commit.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Udr6MfaFLUPhX5Fgo67Jf5

config/config.template.json

@@ -129,9 +129,6 @@
         "plugin_rotation_order": [],
         "use_short_date_format": true,
         "vegas_scroll": {
-      "live_in_ticker": false,
-      "live_weight": 3,
-      "favorite_live_weight": 5,
             "enabled": false,
             "scroll_speed": 50,
             "separator_width": 32,

docs/ADVANCED_FEATURES.md

@@ -64,98 +64,10 @@ JSON is optional.
 | `target_fps` | `125` | Target frame rate |
 | `buffer_ahead` | `2` | Number of plugins buffered ahead |
 
-This table is a subset — `display.vegas_scroll` supports 30 keys in
+This table is a subset — `display.vegas_scroll` supports 26 keys in
 total. See the full list in
 [CONFIG_REFERENCE.md](CONFIG_REFERENCE.md#displayvegas_scroll--continuous-scroll-mode).
 
-### Live Content in the Ticker
-
-By default, live content **preempts** Vegas mode: while any plugin reports
-live priority, the display controller refuses to run the ticker and shows
-that plugin's full-screen display instead. You get a big readable scoreboard,
-but the marquee stops entirely for the duration of the game.
-
-Set `live_in_ticker` to keep the ticker running and let live content take
-**extra turns inside it** instead:
-
-```json
-"vegas_scroll": {
-  "live_in_ticker": true,
-  "live_weight": 3,
-  "favorite_live_weight": 5
-}
-```
-
-#### Why weights exist
-
-The rotation is otherwise a strict round robin — every plugin appears exactly
-once per cycle. With a dozen plugins enabled, a live score comes round once a
-lap and can be minutes old by the time you see it. A weight of *N* gives a
-plugin *N* slots per cycle.
-
-The slots are placed by **Smooth Weighted Round-Robin**, the same scheduler
-the sports plugins use internally to rotate their own games. The important
-property is that repeats are *spread through the cycle* rather than clumped:
-three appearances in a row followed by a long silence would be worse than not
-boosting at all.
-
-Twelve plugins, with a favorite's baseball game and an ordinary live hockey
-game (`live_weight: 3`, `favorite_live_weight: 5`):
-
-```
-baseball > hockey > weather  > clock  > baseball
-stocks   > news   > flights  > baseball > hockey
-calendar > f1     > music    > baseball > tides
-birds    > hockey > baseball
-```
-
-18 slots for 12 plugins. Baseball appears 5 times, hockey 3, everything else
-once, and no plugin ever appears twice in a row — **including across the seam**
-where the cycle loops back on itself. Smooth Weighted Round-Robin schedules the
-heaviest item first and usually last as well, so the strip would otherwise show
-it twice running at exactly the one join a within-cycle check cannot see. The
-trailing repeat is moved into the widest remaining gap. Where a double is
-unavoidable — a plugin holding most of the slots has to neighbour itself — the
-schedule is left as it is.
-
-#### Where the weight comes from
-
-For each plugin in the rotation, in order:
-
-1. **The plugin's own answer.** If it implements
-   `get_vegas_priority_weight()` and returns a number, that wins. This is the
-   only route for favorite-team awareness — the core can see *that* a game is
-   live, but not *whose*, so a scoreboard has to say so itself.
-2. **The core's default.** When the plugin returns `None` (the base-class
-   default), a plugin where both `has_live_priority()` and `has_live_content()`
-   are true gets `live_weight`.
-3. **Everything else** gets 1.
-
-Because of step 2, **existing plugins need no changes** — any scoreboard with
-`live_priority` enabled already gets extra turns. Step 1 is opt-in, for
-plugins that want to distinguish a favorite's game from any other live game.
-
-Weights are clamped to 1–10. A weight of 1 is no boost; a weight below 1 would
-drop the plugin from the rotation entirely, which is never what is meant.
-
-#### Things worth knowing
-
-- **Weights are per plugin, not per game.** A scoreboard showing four live
-  games still occupies one slot at a time, rotating its own games within that
-  slot using its own `favorite_live_boost`. This controls how often the
-  *plugin* comes round.
-- **The ticker is zero-sum.** Giving baseball 5 slots does not make the cycle
-  faster; it makes the cycle *longer* and everything else proportionally
-  rarer. If you want live scores sooner in wall-clock terms, pair this with a
-  smaller `plugins_per_cycle`.
-- **Frequency is not freshness.** Each appearance redraws from the plugin's
-  current data (`refresh_updated_plugins()` drops cached content when a
-  plugin's data changes), but how current that data is depends on the
-  plugin's own `live_update_interval`. Showing a stale score five times a lap
-  is no better than showing it once.
-- **Everything still appears.** A boost never starves another plugin out of
-  the cycle; low-weight plugins keep their single slot.
-
 ### Per-Plugin Configuration
 
 Override Vegas behavior for specific plugins:

docs/CONFIG_REFERENCE.md

@@ -103,8 +103,7 @@ logical image to multiple chained physical panels.
 ## `display.vegas_scroll` — continuous scroll mode
 
 Read by `src/vegas_mode/config.py` (`VegasScrollConfig.from_config`). See
-[ADVANCED_FEATURES.md](ADVANCED_FEATURES.md) for behavior details, including
-[live content in the ticker](ADVANCED_FEATURES.md#live-content-in-the-ticker).
+[ADVANCED_FEATURES.md](ADVANCED_FEATURES.md) for behavior details.
 
 | Key | Type / default |
 |---|---|
@@ -135,9 +134,6 @@ Read by `src/vegas_mode/config.py` (`VegasScrollConfig.from_config`). See
 | `max_cycle_duration` | int, `240` |
 | `frame_based_scrolling` | bool, `true` — frame-count-based scroll stepping |
 | `scroll_delay` | float, `0.02` — seconds between scroll updates (~50 FPS) |
-| `live_in_ticker` | bool, `false` — keep scrolling during live games instead of handing the display to a full-screen scoreboard |
-| `live_weight` | int, `3` (1–10) — slots per cycle for a plugin with live content |
-| `favorite_live_weight` | int, `5` (1–10) — slots per cycle when a plugin reports a favorite team is live |
 
 ## `sync` — multi-display synchronization
 

docs/PLUGIN_API_REFERENCE.md

@@ -170,47 +170,6 @@ Default returns `False`.
 List of display modes to show during a live takeover. Default returns the
 plugin's `display_modes` from its manifest.
 
-#### `get_vegas_priority_weight() -> Optional[int]`
-
-How many slots per Vegas cycle this plugin should get. Default returns
-`None`, which defers to the core.
-
-The Vegas ticker is otherwise a strict round robin — every plugin appears
-exactly once per cycle — so with a dozen plugins enabled a live score can be
-minutes stale by the time it comes round. A weight of *N* gives the plugin
-*N* slots per cycle, spread evenly through it rather than clumped.
-
-**You usually do not need this.** When the hook returns `None`, the core
-already gives a plugin `vegas_scroll.live_weight` whenever
-`has_live_priority()` and `has_live_content()` are both true. Live sports get
-extra turns with no code at all.
-
-Implement it only when the plugin knows something the core cannot. The
-motivating case is favorite teams — the core can see *that* a game is live,
-but not *whose*:
-
-```python
-def get_vegas_priority_weight(self):
-    if not (self.has_live_priority() and self.has_live_content()):
-        return None                       # let the core decide
-    vegas = self.global_config.get('display', {}).get('vegas_scroll', {})
-    if self._favorite_is_live():
-        return vegas.get('favorite_live_weight', 5)
-    return vegas.get('live_weight', 3)
-```
-
-The weight is per *plugin*, not per game: a scoreboard showing four live games
-still occupies one slot at a time and rotates its own games within it. Values
-are clamped to 1–10 by the caller. An exception here is caught and logged, and
-the core then falls back to its own live-content check — so a plugin whose
-weight calculation is broken still gets `live_weight` for a game that really
-is live, rather than being demoted to 1.
-
-Only consulted when the user has set `vegas_scroll.live_in_ticker`. With the
-default (`false`) live content preempts Vegas entirely and there is no ticker
-to be weighted within. See
-[ADVANCED_FEATURES.md](ADVANCED_FEATURES.md#live-content-in-the-ticker).
-
 ### Vegas scroll hooks
 
 Vegas mode shows multiple plugins as a single continuous scroll instead of

src/display_controller.py

@@ -1638,12 +1638,6 @@ class DisplayController:
                 logger.warning("Error checking live priority for %s: %s", mode_name, e)
         return live
 
-    def _vegas_keeps_live_in_ticker(self) -> bool:
-        """Whether live content should stay in the ticker instead of preempting it."""
-        coordinator = getattr(self, 'vegas_coordinator', None)
-        config = getattr(coordinator, 'vegas_config', None)
-        return bool(getattr(config, 'live_in_ticker', False))
-
     def _check_live_priority(self, advance=False):
         """Return the live-priority mode to display, or None if nothing is live.
 
@@ -1857,24 +1851,14 @@ class DisplayController:
                 # Check for live priority content and switch to it immediately.
                 # advance=True so multiple simultaneously-live games take turns
                 # (round-robin) instead of pinning to the first plugin.
-                # Skipped when the ticker is keeping live content: switching
-                # the rotation underneath Vegas would move current_mode_index
-                # and stash a resume point for a takeover that never happens.
-                if (not self.on_demand_active and not wifi_status_data
-                        and not (self._is_vegas_mode_active()
-                                 and self._vegas_keeps_live_in_ticker())):
+                if not self.on_demand_active and not wifi_status_data:
                     live_priority_mode = self._check_live_priority(advance=True)
                     self._apply_live_priority(live_priority_mode)
 
                 # Vegas scroll mode - continuous ticker across all plugins
                 # Priority: on-demand > wifi-status > live-priority > vegas > normal rotation
                 if self._is_vegas_mode_active() and not wifi_status_data:
-                    # Live content normally preempts the ticker entirely. With
-                    # vegas_scroll.live_in_ticker the marquee keeps running and
-                    # the live plugin takes extra turns inside it instead --
-                    # see StreamManager._apply_priority_weights.
-                    live_mode = (None if self._vegas_keeps_live_in_ticker()
-                                 else self._check_live_priority())
+                    live_mode = self._check_live_priority()
                     if not live_mode:
                         try:
                             # Run Vegas mode iteration

src/plugin_system/base_plugin.py

@@ -555,48 +555,6 @@ class BasePlugin(ABC):
         """
         return False
 
-    def get_vegas_priority_weight(self) -> Optional[int]:
-        """How many slots per Vegas cycle this plugin should get, or None.
-
-        The Vegas ticker is otherwise a strict round robin: every plugin
-        appears exactly once per cycle. With a dozen plugins enabled that puts
-        minutes between a live score and its next appearance. A weight of N
-        gives the plugin N slots per cycle, spread evenly through it rather
-        than clumped together.
-
-        Return ``None`` (the default) to let the core decide. It gives a
-        plugin ``vegas_scroll.live_weight`` when ``has_live_priority()`` and
-        ``has_live_content()`` are both true, and 1 otherwise -- so live sports
-        already get extra turns without implementing this at all.
-
-        Implement it only when the plugin knows something the core cannot. The
-        motivating case is favorite teams: the core can see *that* a game is
-        live but not *whose*, so a scoreboard that wants its favorite's game
-        shown more often than other live games has to say so::
-
-            def get_vegas_priority_weight(self):
-                if not (self.has_live_priority() and self.has_live_content()):
-                    return None                      # let the core decide
-                cfg = self.global_config.get('display', {}).get('vegas_scroll', {})
-                if self._favorite_is_live():
-                    return cfg.get('favorite_live_weight', 5)
-                return cfg.get('live_weight', 3)
-
-        The weight is per *plugin*, not per game. A scoreboard showing four
-        live games still occupies one slot at a time and rotates its own games
-        within that slot; this controls how often the plugin itself comes
-        round.
-
-        Raising is safe: the core logs it and falls back to its own
-        live-content check, so a broken weight calculation costs the plugin
-        the favorite distinction but not the live boost.
-
-        Returns:
-            Slots per cycle (clamped to 1..10 by the caller), or None to
-            defer to the core's own live-content weighting.
-        """
-        return None
-
     def get_live_modes(self) -> List[str]:
         """
         Get list of display modes that should be used during live priority takeover.

src/vegas_mode/config.py

@@ -125,32 +125,6 @@ class VegasModeConfig:
     plugin_order: List[str] = field(default_factory=list)
     excluded_plugins: Set[str] = field(default_factory=set)
 
-    # --- Live content in the ticker -------------------------------------
-    #
-    # By default a live game preempts Vegas entirely: the display controller
-    # refuses to run the ticker while any plugin reports live priority, and you
-    # get the full-screen scoreboard instead. Set live_in_ticker to keep the
-    # marquee running and let live content take extra turns within it.
-    #
-    # The rotation is otherwise a strict round robin -- every plugin appears
-    # exactly once per cycle -- so with a dozen plugins enabled a live score
-    # comes round once a lap and can be minutes old on screen. Weighting lets a
-    # plugin claim several slots per cycle instead.
-    #
-    # Weights are per plugin, not per game: a scoreboard showing four live
-    # games still occupies one slot at a time, and rotates its own games within
-    # that slot using its own favorite_live_boost.
-    live_in_ticker: bool = False
-
-    # Slots per cycle for a plugin reporting live content. 1 disables the boost
-    # and restores the plain round robin.
-    live_weight: int = 3
-
-    # Slots per cycle for a plugin whose live content involves a favorite team.
-    # Only plugins implementing get_vegas_priority_weight() can claim this --
-    # the core cannot tell whose game is on, so the plugin reports it.
-    favorite_live_weight: int = 5
-
     # Performance settings
     target_fps: int = 125  # Target frame rate
     buffer_ahead: int = 2  # Number of plugins to buffer ahead
@@ -201,12 +175,6 @@ class VegasModeConfig:
             overflow_mode=str(vegas_config.get('overflow_mode', 'rotate')),
             plugin_order=list(vegas_config.get('plugin_order', [])),
             excluded_plugins=set(vegas_config.get('excluded_plugins', [])),
-            live_in_ticker=bool(vegas_config.get('live_in_ticker', False)),
-            # Clamped: a weight below 1 would drop the plugin from the rotation
-            # entirely, and a very large one starves everything else.
-            live_weight=max(1, min(10, int(vegas_config.get('live_weight', 3)))),
-            favorite_live_weight=max(
-                1, min(10, int(vegas_config.get('favorite_live_weight', 5)))),
             target_fps=int(vegas_config.get('target_fps', 125)),
             buffer_ahead=int(vegas_config.get('buffer_ahead', 2)),
             frame_based_scrolling=vegas_config.get('frame_based_scrolling', True),
@@ -236,9 +204,6 @@ class VegasModeConfig:
             'lead_in_width': self.lead_in_width,
             'plugins_per_cycle': self.plugins_per_cycle,
             'max_plugin_width_ratio': self.max_plugin_width_ratio,
-            'live_in_ticker': self.live_in_ticker,
-            'live_weight': self.live_weight,
-            'favorite_live_weight': self.favorite_live_weight,
             'overflow_mode': self.overflow_mode,
             'plugin_order': self.plugin_order,
             'excluded_plugins': list(self.excluded_plugins),
@@ -406,15 +371,6 @@ class VegasModeConfig:
 
         if 'enabled' in vegas_config:
             self.enabled = vegas_config['enabled']
-        if 'live_in_ticker' in vegas_config:
-            self.live_in_ticker = bool(vegas_config['live_in_ticker'])
-        # Clamped exactly as from_config does: a weight below 1 would drop the
-        # plugin from the rotation, and a huge one starves everything else.
-        if 'live_weight' in vegas_config:
-            self.live_weight = max(1, min(10, int(vegas_config['live_weight'])))
-        if 'favorite_live_weight' in vegas_config:
-            self.favorite_live_weight = max(
-                1, min(10, int(vegas_config['favorite_live_weight'])))
         if 'scroll_speed' in vegas_config:
             self.scroll_speed = float(vegas_config['scroll_speed'])
         if 'separator_width' in vegas_config:

src/vegas_mode/coordinator.py

@@ -497,12 +497,6 @@ class VegasModeCoordinator:
         if not self._live_priority_check:
             return False
 
-        if self.vegas_config.live_in_ticker:
-            # The ticker keeps live content rather than yielding to it; the
-            # extra turns are arranged in the rotation itself, so there is
-            # nothing to pause for.
-            return False
-
         try:
             live_mode = self._live_priority_check()
             if live_mode:

src/vegas_mode/stream_manager.py

@@ -406,8 +406,6 @@ class StreamManager:
         )
         logger.info("Ordered plugins: %s", ordered_plugins)
 
-        ordered_plugins = self._apply_priority_weights(ordered_plugins)
-
         # Atomically update shared state under lock to avoid races with prefetchers
         with self._buffer_lock:
             self._ordered_plugins = ordered_plugins
@@ -419,130 +417,6 @@ class StreamManager:
 
         logger.info("=" * 60)
 
-    def _plugin_weight(self, plugin_id: str) -> int:
-        """Slots per cycle for one plugin.
-
-        A plugin may answer for itself via get_vegas_priority_weight() -- the
-        only way favorite-team awareness can reach here, since the core can see
-        that a game is live but not whose. When it declines (returns None, the
-        default), live content earns ``live_weight`` and everything else 1.
-        """
-        plugin = None
-        try:
-            plugin = self.plugin_manager.plugins.get(plugin_id)
-        except (AttributeError, TypeError):
-            return 1
-        if plugin is None:
-            return 1
-
-        try:
-            if hasattr(plugin, 'get_vegas_priority_weight'):
-                declared = plugin.get_vegas_priority_weight()
-                if declared is not None:
-                    return max(1, min(10, int(declared)))
-        except Exception:
-            # Deliberately falls through to the core's own live check rather
-            # than demoting to 1. The plugin's weight calculation is broken,
-            # but has_live_priority() and has_live_content() are separate
-            # methods guarded separately below -- a plugin that genuinely has
-            # a live game should still get live_weight for it.
-            logger.exception("[%s] get_vegas_priority_weight() failed", plugin_id)
-
-        try:
-            if (hasattr(plugin, 'has_live_priority')
-                    and hasattr(plugin, 'has_live_content')
-                    and plugin.has_live_priority()
-                    and plugin.has_live_content()):
-                return self.config.live_weight
-        except Exception:
-            logger.exception("[%s] live-content check failed", plugin_id)
-        return 1
-
-    def _apply_priority_weights(self, ordered: List[str]) -> List[str]:
-        """Expand the rotation so weighted plugins take several turns per cycle.
-
-        Smooth Weighted Round-Robin, the same scheduler the sports plugins use
-        to rotate their own games: a plugin of weight N appears N times per
-        cycle, and the repeats are spaced through the cycle rather than
-        clumped, so a live score is never three-in-a-row followed by a long
-        silence.
-
-        Returns the input unchanged when nothing is weighted, which is both the
-        common case and the pre-existing behaviour.
-        """
-        if not ordered or not self.config.live_in_ticker:
-            return ordered
-
-        weights = {pid: self._plugin_weight(pid) for pid in ordered}
-        total = sum(weights.values())
-        if total <= len(ordered):
-            return ordered          # nothing boosted; plain round robin
-
-        current = {pid: 0 for pid in ordered}
-        schedule: List[str] = []
-        for _ in range(total):
-            for pid in ordered:
-                current[pid] += weights[pid]
-            picked = max(current, key=lambda p: current[p])
-            current[picked] -= total
-            schedule.append(picked)
-
-        schedule = self._unclump_seam(schedule)
-
-        boosted = {p: w for p, w in weights.items() if w > 1}
-        logger.info(
-            "Vegas rotation weighted: %d slots for %d plugins (boosted: %s)",
-            len(schedule), len(ordered), boosted)
-        return schedule
-
-    @staticmethod
-    def _unclump_seam(schedule: List[str]) -> List[str]:
-        """Stop the heaviest plugin sitting on both ends of the cycle.
-
-        Smooth Weighted Round-Robin spaces repeats well *within* a pass, but
-        it schedules the heaviest item first and often last too. The strip
-        loops, so those two are neighbours: the one place the marquee shows
-        the same plugin twice running is the seam between cycles.
-
-        Rotating the list cannot fix this. Rotation preserves the cyclic order
-        exactly, so it only moves where the seam is drawn, not the adjacency
-        itself. The trailing entry has to be swapped with one from the middle
-        whose neighbours differ from it, which breaks the pair without
-        creating another.
-
-        Left alone when no such position exists -- a rotation short enough or
-        lopsided enough to have none is one where the plugin is unavoidably
-        adjacent to itself anyway.
-        """
-        if len(schedule) < 3 or schedule[0] != schedule[-1]:
-            return schedule
-
-        repeated = schedule[-1]
-        size = len(schedule)
-        elsewhere = [i for i, p in enumerate(schedule[:-1]) if p == repeated]
-
-        def clearance(j: int) -> int:
-            """Cyclic distance from j to the nearest other appearance."""
-            return min(min((i - j) % size, (j - i) % size) for i in elsewhere)
-
-        candidates = [
-            j for j in range(1, size - 1)
-            if schedule[j] != repeated
-            and schedule[j - 1] != repeated
-            and schedule[j + 1] != repeated
-        ]
-        if not candidates:
-            return schedule
-
-        # Drop it into the widest gap rather than the first slot that fits.
-        # Taking the first one undoes the spacing this whole function exists
-        # to protect: on a 28-slot rotation it moved a repeat from a gap of 7
-        # to a gap of 2, which is more clumped than the seam ever was.
-        best = max(candidates, key=clearance) if elsewhere else candidates[0]
-        schedule = list(schedule)
-        schedule[best], schedule[-1] = schedule[-1], schedule[best]
-        return schedule
-
     def _prefetch_content(self, count: int = 1) -> None:
         """
         Prefetch content for upcoming plugins.

src/web_interface/error_handler.py

@@ -77,6 +77,25 @@ def describe_exception(exc: BaseException,
     """
     message = str(exc).strip()
     text = f"{type(exc).__name__}: {message}" if message else type(exc).__name__
+    return redact_text(text, max_length)
+
+
+def redact_text(text: str, max_length: int = _MAX_DETAIL_LENGTH) -> str:
+    """Make arbitrary text safe to hand back over HTTP.
+
+    Split out of describe_exception because exceptions are not the only thing
+    worth returning: a subprocess's stderr, or a message a helper script
+    printed, is just as useful to a user and just as capable of carrying a
+    token or a password in it.
+
+    Args:
+        text: The text to redact
+        max_length: Truncate beyond this many characters
+
+    Returns:
+        A single line, credentials replaced, length capped.
+    """
+    text = text or ''
     # Order matters: the URL and header forms are more specific than the
     # generic key=value pattern, which would otherwise chew the scheme.
     text = _REDACT_URL_USERINFO.sub(r'\1<redacted>\3', text)

test/test_vegas_live_weighting.py

@@ -1,262 +0,0 @@
-"""Tests that live content can take extra turns inside the Vegas ticker.
-
-Vegas was a strict round robin -- every plugin exactly once per cycle -- and
-live content did not appear in it at all, because the display controller
-refused to run the ticker while anything was live. With a dozen plugins
-enabled that left a live score either absent or minutes stale.
-
-Two things change, both off by default. `live_in_ticker` keeps the marquee
-running instead of yielding to a full-screen takeover, and the rotation is
-expanded by Smooth Weighted Round-Robin so a weighted plugin gets several
-slots per cycle, spaced through it rather than clumped.
-
-Weights are per plugin, not per game: a scoreboard showing four live games
-still occupies one slot at a time and rotates its own games within it.
-"""
-
-from unittest.mock import Mock
-
-import pytest
-
-from src.vegas_mode.config import VegasModeConfig
-from src.vegas_mode.stream_manager import StreamManager
-
-
-class FakePlugin:
-    """A plugin that can fail in each place independently.
-
-    hook_raises and live_raises are separate because they mean different
-    things: a broken weight calculation should still leave the core's own
-    live-content check usable, while a plugin that cannot answer whether it is
-    live at all has nothing left to fall back on.
-    """
-
-    def __init__(self, live=False, declared=None, raises=False,
-                 hook_raises=False, live_raises=False):
-        self._live = live
-        self._declared = declared
-        self._hook_raises = hook_raises or raises
-        self._live_raises = live_raises or raises
-        self.enabled = True
-
-    def has_live_priority(self):
-        if self._live_raises:
-            raise RuntimeError("cannot say whether I am live")
-        return self._live
-
-    def has_live_content(self):
-        return self._live
-
-    def get_vegas_priority_weight(self):
-        if self._hook_raises:
-            raise RuntimeError("weight calculation blew up")
-        return self._declared
-
-
-def _manager(plugins, **cfg):
-    config = VegasModeConfig(live_in_ticker=cfg.pop('live_in_ticker', True), **cfg)
-    pm = Mock()
-    pm.plugins = plugins
-    sm = StreamManager.__new__(StreamManager)
-    sm.config = config
-    sm.plugin_manager = pm
-    return sm
-
-
-def _counts(schedule):
-    return {p: schedule.count(p) for p in set(schedule)}
-
-
-def _max_gap(schedule, plugin_id):
-    """Largest gap between consecutive appearances, wrapping around."""
-    at = [i for i, p in enumerate(schedule) if p == plugin_id]
-    if len(at) < 2:
-        return len(schedule)
-    gaps = [b - a for a, b in zip(at, at[1:])]
-    gaps.append(len(schedule) - at[-1] + at[0])
-    return max(gaps)
-
-
-class TestWeightsComeFromTheRightPlace:
-    def test_a_quiet_plugin_gets_one_slot(self):
-        sm = _manager({'clock': FakePlugin()})
-        assert sm._plugin_weight('clock') == 1
-
-    def test_live_content_earns_the_configured_weight(self):
-        sm = _manager({'mlb': FakePlugin(live=True)}, live_weight=4)
-        assert sm._plugin_weight('mlb') == 4
-
-    def test_a_plugin_may_answer_for_itself(self):
-        # The only route for favorite-team awareness: the core can see that a
-        # game is live, not whose.
-        sm = _manager({'mlb': FakePlugin(live=True, declared=7)}, live_weight=3)
-        assert sm._plugin_weight('mlb') == 7
-
-    def test_declaring_none_defers_to_the_core(self):
-        sm = _manager({'mlb': FakePlugin(live=True, declared=None)}, live_weight=3)
-        assert sm._plugin_weight('mlb') == 3
-
-    def test_a_declared_weight_is_clamped(self):
-        sm = _manager({'a': FakePlugin(declared=99), 'b': FakePlugin(declared=0)})
-        assert sm._plugin_weight('a') == 10
-        assert sm._plugin_weight('b') == 1
-
-    def test_a_plugin_that_raises_everywhere_weighs_one(self):
-        sm = _manager({'bad': FakePlugin(raises=True)})
-        assert sm._plugin_weight('bad') == 1
-
-    def test_a_broken_hook_still_earns_the_live_boost(self):
-        # The hook is only how a plugin asks for *more* than live_weight.
-        # Losing it should cost the favorite distinction, not the live boost:
-        # has_live_priority/has_live_content are separate and still work.
-        sm = _manager({'mlb': FakePlugin(live=True, hook_raises=True)},
-                      live_weight=4)
-        assert sm._plugin_weight('mlb') == 4
-
-    def test_a_broken_hook_on_a_quiet_plugin_weighs_one(self):
-        sm = _manager({'clock': FakePlugin(live=False, hook_raises=True)},
-                      live_weight=4)
-        assert sm._plugin_weight('clock') == 1
-
-    def test_a_plugin_that_cannot_say_whether_it_is_live_weighs_one(self):
-        # Nothing left to fall back on, so no boost.
-        sm = _manager({'mlb': FakePlugin(live=True, live_raises=True)},
-                      live_weight=4)
-        assert sm._plugin_weight('mlb') == 1
-
-    def test_an_unknown_plugin_weighs_one(self):
-        assert _manager({})._plugin_weight('ghost') == 1
-
-
-class TestTheSchedule:
-    def test_nothing_weighted_leaves_the_order_untouched(self):
-        order = ['weather', 'clock', 'news']
-        sm = _manager({p: FakePlugin() for p in order})
-        assert sm._apply_priority_weights(order) == order
-
-    def test_off_by_default_the_order_is_untouched(self):
-        order = ['weather', 'mlb', 'news']
-        sm = _manager({'weather': FakePlugin(), 'mlb': FakePlugin(live=True),
-                       'news': FakePlugin()}, live_in_ticker=False, live_weight=3)
-        assert sm._apply_priority_weights(order) == order
-
-    def test_a_live_plugin_takes_its_share_of_slots(self):
-        order = ['weather', 'mlb', 'news', 'clock']
-        sm = _manager({'weather': FakePlugin(), 'mlb': FakePlugin(live=True),
-                       'news': FakePlugin(), 'clock': FakePlugin()},
-                      live_weight=3)
-        schedule = sm._apply_priority_weights(order)
-        counts = _counts(schedule)
-        assert counts['mlb'] == 3, counts
-        assert counts['weather'] == counts['news'] == counts['clock'] == 1, counts
-        assert len(schedule) == 6
-
-    def test_every_plugin_still_appears(self):
-        # A boost must not starve anything out of the cycle.
-        order = ['a', 'b', 'c', 'd', 'e', 'f']
-        plugins = {p: FakePlugin() for p in order}
-        plugins['a'] = FakePlugin(live=True, declared=10)
-        sm = _manager(plugins)
-        schedule = sm._apply_priority_weights(order)
-        assert set(schedule) == set(order), set(order) - set(schedule)
-
-    def test_nothing_doubles_across_the_cycle_seam(self):
-        # The strip loops, so the last slot neighbours the first. Smooth
-        # Weighted Round-Robin schedules the heaviest item first and often
-        # last too, which put the one clump the algorithm exists to avoid at
-        # the one place a within-cycle check cannot see.
-        order = ['baseball', 'weather', 'geochron', 'flights', 'stocks',
-                 'oftheday', 'youtube', 'stocknews', 'leaderboard',
-                 'countdown', 'odds', 'f1', 'football', 'music']
-        plugins = {p: FakePlugin() for p in order}
-        plugins['baseball'] = FakePlugin(live=True, declared=5)
-        plugins['football'] = FakePlugin(live=True, declared=3)
-        schedule = _manager(plugins)._apply_priority_weights(order)
-
-        n = len(schedule)
-        doubles = [schedule[i] for i in range(n)
-                   if schedule[i] == schedule[(i + 1) % n]]
-        assert not doubles, "%r repeats across the seam in %r" % (doubles, schedule)
-
-    def test_the_seam_repair_keeps_every_slot(self):
-        order = ['a', 'b', 'c', 'd', 'e', 'f']
-        plugins = {p: FakePlugin() for p in order}
-        plugins['a'] = FakePlugin(live=True, declared=4)
-        schedule = _manager(plugins)._apply_priority_weights(order)
-        assert _counts(schedule)['a'] == 4, _counts(schedule)
-        assert sorted(schedule) == sorted(
-            ['a'] * 4 + ['b', 'c', 'd', 'e', 'f']), schedule
-
-    def test_the_repair_uses_the_widest_gap(self):
-        # Moving the trailing repeat into the first slot that merely fits
-        # undoes the spacing: on a 28-slot rotation that turned a gap of 7
-        # into a gap of 2, which is more clumped than the seam ever was.
-        order = ['a'] + ['p%d' % i for i in range(13)]
-        plugins = {p: FakePlugin() for p in order}
-        plugins['a'] = FakePlugin(live=True, declared=4)
-        schedule = _manager(plugins)._apply_priority_weights(order)
-        at = [i for i, p in enumerate(schedule) if p == 'a']
-        gaps = [b - a for a, b in zip(at, at[1:])]
-        gaps.append(len(schedule) - at[-1] + at[0])
-        ideal = len(schedule) / len(at)
-        assert min(gaps) >= ideal / 2, "gaps %r for ideal %.1f" % (gaps, ideal)
-
-    def test_an_unavoidable_double_is_left_alone(self):
-        # Five of seven slots are the same plugin, so it must neighbour
-        # itself. Better to schedule it than to refuse or loop forever.
-        order = ['a', 'b', 'c']
-        plugins = {p: FakePlugin() for p in order}
-        plugins['a'] = FakePlugin(live=True, declared=5)
-        schedule = _manager(plugins)._apply_priority_weights(order)
-        assert _counts(schedule) == {'a': 5, 'b': 1, 'c': 1}, _counts(schedule)
-        assert set(schedule) == {'a', 'b', 'c'}
-
-    def test_a_schedule_too_short_to_repair_is_returned_as_is(self):
-        sm = _manager({})
-        assert sm._unclump_seam(['a', 'a']) == ['a', 'a']
-        assert sm._unclump_seam(['a']) == ['a']
-        assert sm._unclump_seam([]) == []
-
-    def test_a_schedule_with_no_seam_clash_is_untouched(self):
-        sm = _manager({})
-        plain = ['a', 'b', 'c', 'a', 'd']
-        assert sm._unclump_seam(plain) == plain
-
-    def test_repeats_are_spread_not_clumped(self):
-        # The point of Smooth Weighted Round-Robin. Three-in-a-row followed by
-        # a long silence would be worse than not boosting at all.
-        order = ['weather', 'mlb', 'news', 'clock', 'stocks', 'f1']
-        plugins = {p: FakePlugin() for p in order}
-        plugins['mlb'] = FakePlugin(live=True)
-        sm = _manager(plugins, live_weight=3)
-        schedule = sm._apply_priority_weights(order)
-
-        assert _counts(schedule)['mlb'] == 3
-        # Evenly spread over 8 slots means a gap of about 3, never 6.
-        assert _max_gap(schedule, 'mlb') <= 4, schedule
-        # And never twice running.
-        assert not any(a == b == 'mlb' for a, b in zip(schedule, schedule[1:])), schedule
-
-    def test_a_favorite_outranks_another_live_game(self):
-        order = ['weather', 'mlb', 'nhl']
-        sm = _manager({'weather': FakePlugin(),
-                       'mlb': FakePlugin(live=True, declared=5),
-                       'nhl': FakePlugin(live=True)}, live_weight=2)
-        counts = _counts(sm._apply_priority_weights(order))
-        assert counts['mlb'] == 5 and counts['nhl'] == 2 and counts['weather'] == 1, counts
-
-    def test_an_empty_rotation_is_harmless(self):
-        assert _manager({})._apply_priority_weights([]) == []
-
-
-class TestConfigParsing:
-    def test_defaults_preserve_todays_behaviour(self):
-        cfg = VegasModeConfig.from_config({})
-        assert cfg.live_in_ticker is False
-        assert cfg.live_weight == 3 and cfg.favorite_live_weight == 5
-
-    @pytest.mark.parametrize("given,expected", [(0, 1), (-4, 1), (99, 10), (4, 4)])
-    def test_weights_are_clamped(self, given, expected):
-        cfg = VegasModeConfig.from_config(
-            {'display': {'vegas_scroll': {'live_weight': given}}})
-        assert cfg.live_weight == expected

test/web_interface/test_calendar_oauth_endpoints.py

@@ -0,0 +1,344 @@
+"""Tests the calendar plugin's OAuth and calendar-listing endpoints.
+
+The plugin's config UI advertised a three-step setup, but only step 1 existed
+on the server. Step 3's picker fetched /api/v3/plugins/calendar/list-calendars,
+which was never registered, so Flask fell through to the global 404 handler and
+the user saw "Resource not found" — with nothing to say which resource. Step 2
+had no endpoint either, and no field in the schema at all, even though the
+plugin ships calendar_registration.py written expressly for a web-driven
+two-step flow.
+
+These cover the two new routes: that they exist, that they fail with something
+actionable rather than a bare 404, and that the shapes the widgets consume are
+what the server actually sends.
+"""
+
+import json
+import pickle
+import sys
+from pathlib import Path
+
+import pytest
+
+project_root = Path(__file__).parent.parent.parent
+sys.path.insert(0, str(project_root))
+
+from web_interface.blueprints import api_v3 as mod  # noqa: E402
+
+
+@pytest.fixture
+def client(monkeypatch, tmp_path):
+    """A test client whose calendar plugin lives in tmp_path."""
+    from flask import Flask
+
+    plugin_dir = tmp_path / 'calendar'
+    plugin_dir.mkdir()
+
+    app = Flask(__name__)
+    app.register_blueprint(mod.api_v3, url_prefix='/api/v3')
+    app.config['TESTING'] = True
+    monkeypatch.setattr(mod, '_calendar_plugin_dir', lambda: plugin_dir)
+    with app.test_client() as c:
+        c.plugin_dir = plugin_dir
+        yield c
+
+
+@pytest.fixture
+def uninstalled(monkeypatch):
+    from flask import Flask
+
+    app = Flask(__name__)
+    app.register_blueprint(mod.api_v3, url_prefix='/api/v3')
+    app.config['TESTING'] = True
+    monkeypatch.setattr(mod, '_calendar_plugin_dir', lambda: None)
+    with app.test_client() as c:
+        yield c
+
+
+class TestTheRoutesExistAtAll:
+    """The original bug: the URLs the widgets call were not registered."""
+
+    def test_list_calendars_is_routed(self, client):
+        response = client.get('/api/v3/plugins/calendar/list-calendars')
+        # Reaching the handler is the whole point; what it then says about
+        # missing setup is TestItSaysWhatIsWrong's business.
+        assert response.status_code != 404, "still unrouted"
+        assert response.get_json()['message'] != 'Resource not found'
+
+    def test_authenticate_is_routed(self, client):
+        response = client.post('/api/v3/plugins/calendar/authenticate', json={})
+        assert response.status_code != 404, "still unrouted"
+        assert response.get_json()['message'] != 'Resource not found'
+
+    def test_both_urls_match_what_the_widgets_request(self):
+        # The widgets hardcode these; a rename on either side reintroduces the
+        # original bug silently.
+        picker = Path(project_root) / 'web_interface/static/v3/js/widgets/google-calendar-picker.js'
+        oauth = Path(project_root) / 'web_interface/static/v3/js/widgets/google-oauth.js'
+        assert '/api/v3/plugins/calendar/list-calendars' in picker.read_text(encoding='utf-8')
+        assert '/api/v3/plugins/calendar/authenticate' in oauth.read_text(encoding='utf-8')
+        source = (Path(project_root) / 'web_interface/blueprints/api_v3.py').read_text(encoding='utf-8')
+        assert "'/plugins/calendar/list-calendars'" in source
+        assert "'/plugins/calendar/authenticate'" in source
+
+    def test_the_oauth_widget_is_dispatched_not_rendered_as_a_text_box(self):
+        # The string branch of the config template dispatches on an allow-list
+        # of widget names; anything missing from it silently falls through to a
+        # plain <input type="text">. That produced two boxes on the calendar
+        # page -- the widget's own, and a stray one for the same field -- and
+        # no way to tell which to paste into.
+        template = (Path(project_root)
+                    / 'web_interface/templates/v3/partials/plugin_config.html'
+                    ).read_text(encoding='utf-8')
+        allow_list_line = [ln for ln in template.splitlines()
+                           if "str_widget in [" in ln]
+        assert allow_list_line, "the string widget allow-list moved"
+        assert "'google-oauth'" in allow_list_line[0], allow_list_line[0]
+
+    def test_the_widget_script_is_served(self):
+        base = (Path(project_root) / 'web_interface/templates/v3/base.html'
+                ).read_text(encoding='utf-8')
+        assert 'widgets/google-oauth.js' in base
+
+    def test_the_failed_page_is_called_out_loudly(self):
+        # The loopback redirect lands on a browser error page at exactly the
+        # moment the user has to act. In small grey text it gets missed and the
+        # flow reads as broken while it is working.
+        widget = (Path(project_root)
+                  / 'web_interface/static/v3/js/widgets/google-oauth.js'
+                  ).read_text(encoding='utf-8')
+        assert 'expected' in widget.lower()
+        assert 'amber' in widget, "the warning is not visually distinguished"
+
+
+class TestItSaysWhatIsWrong:
+    def test_listing_without_a_token_asks_for_step_2(self, client):
+        response = client.get('/api/v3/plugins/calendar/list-calendars')
+        assert response.status_code == 400
+        body = response.get_json()
+        assert body['status'] == 'error'
+        assert 'step 2' in body['message'].lower(), body['message']
+
+    def test_authenticating_without_credentials_asks_for_step_1(self, client):
+        response = client.post('/api/v3/plugins/calendar/authenticate', json={})
+        assert response.status_code == 400
+        assert 'step 1' in response.get_json()['message'].lower()
+
+    def test_an_uninstalled_plugin_says_so(self, uninstalled):
+        for response in (
+            uninstalled.get('/api/v3/plugins/calendar/list-calendars'),
+            uninstalled.post('/api/v3/plugins/calendar/authenticate', json={}),
+        ):
+            assert response.status_code == 404
+            # A 404 here is honest -- but it must name the plugin, not read as
+            # the generic "Resource not found" that started this.
+            assert 'not installed' in response.get_json()['message'].lower()
+
+
+class TestTheScriptRunner:
+    def test_it_returns_the_json_the_script_prints(self, tmp_path):
+        script = tmp_path / 'calendar_registration.py'
+        script.write_text(
+            'print(\'{"status": "success", "auth_url": "https://x"}\')\n',
+            encoding='utf-8')
+        payload, error = mod._run_calendar_registration(tmp_path, '')
+        assert error is None
+        assert payload['auth_url'] == 'https://x'
+
+    def test_it_ignores_noise_before_the_json(self, tmp_path):
+        # An import warning or a library writing to stdout would otherwise
+        # make the last-line parse fail.
+        script = tmp_path / 'calendar_registration.py'
+        script.write_text(
+            'print("some library warning")\n'
+            'print(\'{"status": "success"}\')\n', encoding='utf-8')
+        payload, error = mod._run_calendar_registration(tmp_path, '')
+        assert error is None and payload['status'] == 'success'
+
+    def test_it_passes_stdin_through(self, tmp_path):
+        script = tmp_path / 'calendar_registration.py'
+        script.write_text(
+            'import sys, json\n'
+            'print(json.dumps({"status": "success", "got": sys.stdin.read().strip()}))\n',
+            encoding='utf-8')
+        payload, _ = mod._run_calendar_registration(tmp_path, 'http://127.0.0.1/?code=abc')
+        assert payload['got'] == 'http://127.0.0.1/?code=abc'
+
+    def test_a_missing_script_is_reported(self, tmp_path):
+        payload, error = mod._run_calendar_registration(tmp_path, '')
+        assert payload is None
+        assert 'script not found' in error.lower()
+
+    def test_output_that_is_not_json_is_reported_with_context(self, tmp_path):
+        script = tmp_path / 'calendar_registration.py'
+        script.write_text('import sys\nsys.stderr.write("boom\\n")\n', encoding='utf-8')
+        payload, error = mod._run_calendar_registration(tmp_path, '')
+        assert payload is None
+        assert 'no result' in error.lower()
+        assert 'boom' in error
+
+
+class TestListingShape:
+    """The picker reads cal.id, cal.summary and cal.primary."""
+
+    def _authenticate(self, client, monkeypatch, items):
+        creds = type('C', (), {'expired': False, 'refresh_token': None, 'valid': True})()
+        (client.plugin_dir / 'token.pickle').write_bytes(pickle.dumps({'x': 1}))
+        monkeypatch.setattr(mod.pickle if hasattr(mod, 'pickle') else pickle,
+                            'loads', lambda *a, **k: creds, raising=False)
+
+        import types
+        fake_pickle = types.SimpleNamespace(load=lambda f: creds, dump=lambda *a: None)
+        pages = items if isinstance(items, list) and items and isinstance(items[0], dict) \
+            else items
+        if isinstance(pages, list):
+            pages = [{'items': pages}]
+
+        state = {'i': 0}
+
+        def fake_list(**kwargs):
+            page = pages[min(state['i'], len(pages) - 1)]
+            state['i'] += 1
+            return types.SimpleNamespace(execute=lambda: page)
+
+        def fake_build(*args, **kwargs):
+            return types.SimpleNamespace(
+                calendarList=lambda: types.SimpleNamespace(list=fake_list))
+
+        real_import = __builtins__['__import__'] if isinstance(__builtins__, dict) \
+            else __builtins__.__import__
+
+        def fake_import(name, *args, **kwargs):
+            if name == 'pickle':
+                return fake_pickle
+            if name == 'google.auth.transport.requests':
+                return types.SimpleNamespace(Request=object)
+            if name == 'googleapiclient.discovery':
+                return types.SimpleNamespace(build=fake_build)
+            return real_import(name, *args, **kwargs)
+
+        monkeypatch.setattr('builtins.__import__', fake_import)
+
+    def test_it_returns_id_summary_and_primary(self, client, monkeypatch):
+        self._authenticate(client, monkeypatch, [
+            {'id': 'b@x', 'summary': 'Work'},
+            {'id': 'a@x', 'summary': 'Personal', 'primary': True},
+        ])
+        body = client.get('/api/v3/plugins/calendar/list-calendars').get_json()
+        assert body['status'] == 'success'
+        assert {c['id'] for c in body['calendars']} == {'a@x', 'b@x'}
+        assert all(set(c) == {'id', 'summary', 'primary'} for c in body['calendars'])
+
+    def test_the_primary_calendar_comes_first(self, client, monkeypatch):
+        # Short list, but the one the user wants is almost always their own.
+        self._authenticate(client, monkeypatch, [
+            {'id': 'z@x', 'summary': 'Aardvarks'},
+            {'id': 'a@x', 'summary': 'Zebras', 'primary': True},
+        ])
+        body = client.get('/api/v3/plugins/calendar/list-calendars').get_json()
+        assert body['calendars'][0]['id'] == 'a@x'
+        assert body['calendars'][0]['primary'] is True
+
+    def test_a_calendar_without_a_name_still_lists(self, client, monkeypatch):
+        self._authenticate(client, monkeypatch, [{'id': 'noname@x'}])
+        body = client.get('/api/v3/plugins/calendar/list-calendars').get_json()
+        assert body['calendars'][0]['summary'] == 'noname@x'
+
+    def test_entries_without_an_id_are_dropped(self, client, monkeypatch):
+        # Nothing could be selected by such a row, and the checkbox value
+        # would be undefined.
+        self._authenticate(client, monkeypatch, [{'summary': 'ghost'}, {'id': 'real@x'}])
+        body = client.get('/api/v3/plugins/calendar/list-calendars').get_json()
+        assert [c['id'] for c in body['calendars']] == ['real@x']
+
+
+class TestPagination:
+    """calendarList.list pages at 250 and defaults to 100."""
+
+    def _paged(self, client, monkeypatch, pages):
+        import types
+        creds = type('C', (), {'expired': False, 'refresh_token': None, 'valid': True})()
+        (client.plugin_dir / 'token.pickle').write_bytes(b'x')
+        state = {'i': 0}
+        seen = []
+
+        def fake_list(**kwargs):
+            seen.append(kwargs)
+            page = pages[min(state['i'], len(pages) - 1)]
+            state['i'] += 1
+            return types.SimpleNamespace(execute=lambda: page)
+
+        def fake_build(*args, **kwargs):
+            return types.SimpleNamespace(
+                calendarList=lambda: types.SimpleNamespace(list=fake_list))
+
+        real_import = __builtins__['__import__'] if isinstance(__builtins__, dict) \
+            else __builtins__.__import__
+
+        def fake_import(name, *args, **kwargs):
+            if name == 'pickle':
+                return types.SimpleNamespace(load=lambda f: creds, dump=lambda *a: None)
+            if name == 'google.auth.transport.requests':
+                return types.SimpleNamespace(Request=object)
+            if name == 'googleapiclient.discovery':
+                return types.SimpleNamespace(build=fake_build)
+            return real_import(name, *args, **kwargs)
+
+        monkeypatch.setattr('builtins.__import__', fake_import)
+        return seen
+
+    def test_every_page_is_collected(self, client, monkeypatch):
+        # Taking only the first page would hide calendars from the picker with
+        # nothing to say the list was cut short.
+        self._paged(client, monkeypatch, [
+            {'items': [{'id': 'a@x', 'summary': 'A'}], 'nextPageToken': 't1'},
+            {'items': [{'id': 'b@x', 'summary': 'B'}], 'nextPageToken': 't2'},
+            {'items': [{'id': 'c@x', 'summary': 'C'}]},
+        ])
+        body = client.get('/api/v3/plugins/calendar/list-calendars').get_json()
+        assert [c['id'] for c in body['calendars']] == ['a@x', 'b@x', 'c@x']
+
+    def test_the_page_token_is_passed_back(self, client, monkeypatch):
+        seen = self._paged(client, monkeypatch, [
+            {'items': [{'id': 'a@x', 'summary': 'A'}], 'nextPageToken': 'tok'},
+            {'items': [{'id': 'b@x', 'summary': 'B'}]},
+        ])
+        client.get('/api/v3/plugins/calendar/list-calendars')
+        assert seen[0]['pageToken'] is None
+        assert seen[1]['pageToken'] == 'tok'
+        assert all(k['maxResults'] == 250 for k in seen)
+
+    def test_a_looping_token_cannot_spin_forever(self, client, monkeypatch):
+        # Every page claims another follows.
+        self._paged(client, monkeypatch, [
+            {'items': [{'id': 'a@x', 'summary': 'A'}], 'nextPageToken': 'same'},
+        ])
+        body = client.get('/api/v3/plugins/calendar/list-calendars').get_json()
+        assert body['status'] == 'success'
+        assert len(body['calendars']) <= mod._CALENDAR_LIST_MAX_PAGES
+
+
+class TestDiagnosticsAreRedacted:
+    def test_script_stderr_is_redacted_on_the_way_out(self, tmp_path):
+        script = tmp_path / 'calendar_registration.py'
+        script.write_text(
+            'import sys\n'
+            'sys.stderr.write("boom client_secret=hunter2 more\\n")\n',
+            encoding='utf-8')
+        payload, error = mod._run_calendar_registration(tmp_path, '')
+        assert payload is None
+        assert 'hunter2' not in error, error
+        assert '<redacted>' in error, error
+
+    def test_a_failing_script_payload_is_redacted(self, client):
+        (client.plugin_dir / 'credentials.json').write_text('{}', encoding='utf-8')
+        (client.plugin_dir / 'calendar_registration.py').write_text(
+            'import json\n'
+            'print(json.dumps({"status": "error", '
+            '"message": "Failed: client_secret=topsecret"}))\n',
+            encoding='utf-8')
+        body = client.post('/api/v3/plugins/calendar/authenticate',
+                           json={}).get_json()
+        assert body['status'] == 'error'
+        assert 'topsecret' not in json.dumps(body), body
+        assert '<redacted>' in body['message'], body

web_interface/blueprints/api_v3.py

@@ -22,7 +22,7 @@ logger = logging.getLogger(__name__)
 from src.web_interface.api_helpers import success_response, error_response, validate_request_json
 from src.web_interface.errors import ErrorCode
 from src.web_interface.secret_helpers import find_secret_fields, separate_secrets
-from src.web_interface.error_handler import describe_exception
+from src.web_interface.error_handler import describe_exception, redact_text
 from src.plugin_system.operation_types import OperationType
 from src.web_interface.validators import (
     validate_file_upload
@@ -7312,6 +7312,222 @@ def upload_calendar_credentials():
         logger.error('Error in upload_calendar_credentials', exc_info=True)
         return jsonify({'status': 'error', 'message': 'An error occurred; see logs for details', 'details': describe_exception(e)}), 500
 
+# calendarList.list pages at 250 entries maximum. Ten pages is far past any
+# real account and exists only so a malformed nextPageToken cannot spin here.
+_CALENDAR_LIST_MAX_PAGES = 10
+
+
+def _calendar_plugin_dir() -> Optional[Path]:
+    """Where the calendar plugin is installed, or None if it is not."""
+    if api_v3.plugin_manager:
+        plugin_dir = api_v3.plugin_manager.get_plugin_directory('calendar')
+    else:
+        plugin_dir = PROJECT_ROOT / 'plugins' / 'calendar'
+    if not plugin_dir:
+        return None
+    plugin_dir = Path(plugin_dir)
+    return plugin_dir if plugin_dir.exists() else None
+
+
+def _run_calendar_registration(plugin_dir: Path, stdin_payload: str):
+    """Run the plugin's OAuth script and return the JSON object it prints.
+
+    The script decides between web and terminal mode by whether stdin is a
+    tty, so it must be given a pipe. It emits one JSON object on stdout; the
+    last parsable line is taken, because an import warning or a library's
+    stderr redirection can land in front of it.
+
+    Returns (payload, error_message). Exactly one is None.
+    """
+    script = plugin_dir / 'calendar_registration.py'
+    if not script.exists():
+        return None, 'Authentication script not found in the calendar plugin'
+
+    try:
+        result = subprocess.run(  # nosec B603 - fixed script path inside the plugin dir
+            [sys.executable, str(script)],
+            input=stdin_payload,
+            capture_output=True,
+            text=True,
+            timeout=120,
+            cwd=str(plugin_dir),
+        )
+    except subprocess.TimeoutExpired:
+        return None, 'Authentication timed out after 120s'
+    except OSError as e:
+        return None, 'Could not run the authentication script: %s' % e
+
+    for line in reversed((result.stdout or '').splitlines()):
+        line = line.strip()
+        if not line:
+            continue
+        try:
+            payload = json.loads(line)
+        except json.JSONDecodeError:
+            continue
+        if isinstance(payload, dict):
+            return payload, None
+
+    raw = (result.stderr or result.stdout or '').strip()
+    # The unredacted text goes to the log, where it is worth having in full.
+    # What comes back over HTTP is redacted: this is a script that handles
+    # OAuth client secrets, and its stderr can quote them.
+    if raw:
+        logger.error('calendar_registration.py failed (exit %s): %s',
+                     result.returncode, raw)
+    return None, 'Authentication script produced no result%s' % (
+        ': %s' % redact_text(raw) if raw else '')
+
+
+@api_v3.route('/plugins/calendar/authenticate', methods=['POST'])
+def authenticate_calendar():
+    """Google OAuth for the calendar plugin, in the two steps it requires.
+
+    Step 1 (no body) returns the consent URL to open. Step 2 posts back the
+    URL Google redirected to -- it fails to load, because the redirect points
+    at a loopback address nothing is listening on, but the address bar carries
+    the authorization code -- and the script exchanges it for a token.
+
+    Two calls rather than one because the user has to visit Google in between.
+    The script persists the PKCE verifier from step 1 for step 2 to reuse; the
+    exchange fails with "Missing code verifier" otherwise.
+    """
+    try:
+        plugin_dir = _calendar_plugin_dir()
+        if plugin_dir is None:
+            return jsonify({
+                'status': 'error',
+                'message': 'The calendar plugin is not installed'
+            }), 404
+
+        if not (plugin_dir / 'credentials.json').exists():
+            return jsonify({
+                'status': 'error',
+                'message': ('No credentials.json yet. Upload your Google OAuth '
+                            'client file first (Step 1).')
+            }), 400
+
+        data = request.get_json(silent=True) or {}
+        redirect_url = (data.get('redirect_url') or data.get('code') or '').strip()
+
+        payload, error = _run_calendar_registration(plugin_dir, redirect_url)
+        if error:
+            return jsonify({'status': 'error', 'message': error}), 500
+        if payload.get('status') != 'success':
+            # The script's own diagnosis is more useful than anything that
+            # could be reconstructed here -- but it interpolates exceptions
+            # into its messages, so it reaches the client redacted and the
+            # original goes to the log.
+            logger.error('calendar authentication failed: %s', payload)
+            safe = dict(payload)
+            safe['message'] = redact_text(str(payload.get('message', '')
+                                              or 'Authentication failed'))
+            return jsonify(safe), 400
+        return jsonify(payload)
+
+    except Exception as e:
+        logger.error('Error in authenticate_calendar', exc_info=True)
+        return jsonify({'status': 'error',
+                        'message': 'An error occurred; see logs for details',
+                        'details': describe_exception(e)}), 500
+
+
+@api_v3.route('/plugins/calendar/list-calendars', methods=['GET'])
+def list_calendar_calendars():
+    """The calendars this account can see, for the config picker.
+
+    Reads the token the OAuth flow wrote rather than shelling out again: the
+    picker is used interactively and a subprocess per click is slower than the
+    API call it would be wrapping.
+    """
+    try:
+        plugin_dir = _calendar_plugin_dir()
+        if plugin_dir is None:
+            return jsonify({
+                'status': 'error',
+                'message': 'The calendar plugin is not installed'
+            }), 404
+
+        token_file = plugin_dir / 'token.pickle'
+        if not token_file.exists():
+            return jsonify({
+                'status': 'error',
+                'message': ('Not authenticated with Google yet. Complete Step 2 '
+                            'first, then load your calendars.')
+            }), 400
+
+        try:
+            import pickle
+            from google.auth.transport.requests import Request as GoogleRequest
+            from googleapiclient.discovery import build as build_google_service
+        except ImportError as e:
+            return jsonify({
+                'status': 'error',
+                'message': ('The Google API libraries are not installed. Install '
+                            "the calendar plugin's requirements.txt. (%s)" % e)
+            }), 500
+
+        with open(token_file, 'rb') as handle:
+            # Written only by this plugin's own OAuth flow, into its own
+            # directory, and read here exactly as the plugin itself reads it.
+            creds = pickle.load(handle)  # nosec B301 - locally generated token
+
+        if creds and creds.expired and creds.refresh_token:
+            creds.refresh(GoogleRequest())
+            with open(token_file, 'wb') as handle:
+                pickle.dump(creds, handle)
+            os.chmod(token_file, 0o600)
+
+        if not creds or not creds.valid:
+            return jsonify({
+                'status': 'error',
+                'message': ('Stored Google credentials are no longer valid. '
+                            'Run Step 2 again to re-authenticate.')
+            }), 400
+
+        service = build_google_service('calendar', 'v3', credentials=creds)
+
+        # calendarList.list returns 100 entries per page by default and caps at
+        # 250, handing back a nextPageToken when there are more. Taking only
+        # the first page would silently hide calendars from the picker, and the
+        # user would have no way to tell the list was truncated.
+        entries = []
+        page_token = None
+        for _ in range(_CALENDAR_LIST_MAX_PAGES):
+            response = service.calendarList().list(
+                maxResults=250, pageToken=page_token).execute()
+            entries.extend(response.get('items', []))
+            page_token = response.get('nextPageToken')
+            if not page_token:
+                break
+        else:
+            # 2500 calendars in, something is wrong with the account or the
+            # token is looping; show what was collected rather than spin.
+            logger.warning(
+                'calendarList paging stopped at %d pages with more remaining',
+                _CALENDAR_LIST_MAX_PAGES)
+
+        calendars = [{
+            'id': entry.get('id'),
+            # The picker labels each row with summary and falls back to the id
+            # only in its own display, so send something either way.
+            'summary': entry.get('summary') or entry.get('id'),
+            'primary': bool(entry.get('primary', False)),
+        } for entry in entries if entry.get('id')]
+
+        # Primary first, then alphabetically: the list is usually short but the
+        # one the user wants is almost always their own calendar.
+        calendars.sort(key=lambda c: (not c['primary'], c['summary'].lower()))
+
+        return jsonify({'status': 'success', 'calendars': calendars})
+
+    except Exception as e:
+        logger.error('Error in list_calendar_calendars', exc_info=True)
+        return jsonify({'status': 'error',
+                        'message': 'An error occurred; see logs for details',
+                        'details': describe_exception(e)}), 500
+
+
 @api_v3.route('/plugins/assets/delete', methods=['POST'])
 def delete_plugin_asset():
     """Delete an asset file for a plugin"""

web_interface/static/v3/js/widgets/google-oauth.js

@@ -0,0 +1,184 @@
+/**
+ * Google OAuth Widget
+ *
+ * Step 2 of the calendar plugin's setup, between uploading the OAuth client
+ * file and picking calendars. Google will not let a headless device complete
+ * consent on its own, so the flow is necessarily two calls with a human in
+ * between:
+ *
+ *   1. POST /api/v3/plugins/calendar/authenticate with no body
+ *      -> { auth_url } to open in a browser
+ *   2. the browser lands on a loopback address that fails to load; its URL
+ *      carries the authorization code. POST it back as redirect_url
+ *      -> the server exchanges it and writes token.pickle
+ *
+ * The failed page in step 2 is expected and is worth saying out loud, because
+ * it looks exactly like something went wrong.
+ *
+ * @module GoogleOAuthWidget
+ */
+
+(function () {
+    'use strict';
+
+    if (typeof window.LEDMatrixWidgets === 'undefined') {
+        console.error('[GoogleOAuthWidget] LEDMatrixWidgets registry not found. Load registry.js first.');
+        return;
+    }
+
+    const ENDPOINT = '/api/v3/plugins/calendar/authenticate';
+
+    window.LEDMatrixWidgets.register('google-oauth', {
+        name: 'Google OAuth Widget',
+        version: '1.0.0',
+
+        /**
+         * @param {HTMLElement} container
+         * @param {Object} config  - schema config (unused)
+         * @param {*}      value   - unused; this widget stores nothing
+         * @param {Object} options - { fieldId, pluginId, name }
+         */
+        render: function (container, config, value, options) {
+            const fieldId = options.fieldId;
+
+            // Nothing is stored in config by this step -- the result is
+            // token.pickle on the device -- but the form still expects a field.
+            const hidden = document.createElement('input');
+            hidden.type = 'hidden';
+            hidden.id = fieldId + '_hidden';
+            hidden.name = options.name;
+            hidden.value = value || '';
+
+            const startBtn = document.createElement('button');
+            startBtn.type = 'button';
+            startBtn.className = 'px-3 py-1.5 text-sm rounded-md bg-blue-600 hover:bg-blue-700 text-white';
+            startBtn.innerHTML = '<i class="fas fa-key"></i> Connect Google Account';
+
+            const status = document.createElement('p');
+            status.className = 'text-xs text-gray-400 mt-2';
+
+            const step2 = document.createElement('div');
+            step2.className = 'mt-3 hidden';
+
+            const link = document.createElement('a');
+            link.target = '_blank';
+            link.rel = 'noopener noreferrer';
+            link.className = 'text-blue-400 underline text-sm break-all';
+            link.textContent = 'Open the Google consent screen';
+
+            // Deliberately loud. After consent the browser is redirected to a
+            // loopback address nothing is listening on, so it lands on a
+            // browser error page -- which reads as a failure at exactly the
+            // moment the user has to act on it. Said quietly in grey it gets
+            // missed, and the flow looks broken when it is working.
+            const hint = document.createElement('div');
+            hint.className =
+                'mt-3 p-3 rounded-md border border-amber-500/60 bg-amber-500/10';
+            hint.innerHTML =
+                '<p class="text-sm text-amber-300 font-semibold">'
+                + '<i class="fas fa-triangle-exclamation"></i> '
+                + 'The next page will fail to load. That is expected.</p>'
+                + '<p class="text-xs text-amber-200/90 mt-1">'
+                + 'After you approve access, Google sends your browser to '
+                + '<code>127.0.0.1</code>, where nothing is running \u2014 so you will see '
+                + '"This site can\u2019t be reached" or similar. Nothing has gone wrong. '
+                + 'Copy the <strong>entire address</strong> out of the address bar '
+                + '(it contains <code>?code=...</code>) and paste it in the box below.</p>';
+
+            const codeLabel = document.createElement('label');
+            codeLabel.className = 'block text-xs text-gray-300 mt-3';
+            codeLabel.textContent = 'Paste the address from that failed page here:';
+
+            const codeInput = document.createElement('input');
+            codeInput.type = 'text';
+            codeInput.placeholder = 'http://127.0.0.1/?code=...';
+            codeInput.className =
+                'mt-2 block w-full px-3 py-2 text-sm border border-gray-600 '
+                + 'rounded-md bg-gray-800 text-gray-100';
+
+            const finishBtn = document.createElement('button');
+            finishBtn.type = 'button';
+            finishBtn.className = 'mt-2 px-3 py-1.5 text-sm rounded-md bg-green-600 hover:bg-green-700 text-white';
+            finishBtn.innerHTML = '<i class="fas fa-check"></i> Finish Authentication';
+
+            function say(message, kind) {
+                status.textContent = message;
+                status.className = 'text-xs mt-2 ' + (
+                    kind === 'error' ? 'text-red-400'
+                        : kind === 'success' ? 'text-green-400'
+                            : 'text-gray-400');
+            }
+
+            function post(body) {
+                return fetch(ENDPOINT, {
+                    method: 'POST',
+                    headers: { 'Content-Type': 'application/json' },
+                    body: JSON.stringify(body || {})
+                }).then(function (r) {
+                    return r.json().catch(function () {
+                        // A non-JSON body here means the request never reached
+                        // the handler -- worth saying so rather than "undefined".
+                        return { status: 'error', message: 'Server returned ' + r.status };
+                    });
+                });
+            }
+
+            startBtn.addEventListener('click', function () {
+                startBtn.disabled = true;
+                say('Requesting a consent link...');
+                post({}).then(function (data) {
+                    startBtn.disabled = false;
+                    if (data.status !== 'success' || !data.auth_url) {
+                        say(data.message || 'Could not start authentication.', 'error');
+                        return;
+                    }
+                    link.href = data.auth_url;
+                    step2.classList.remove('hidden');
+                    say(data.message || 'Open the link, approve, then paste the address back.');
+                }).catch(function (err) {
+                    startBtn.disabled = false;
+                    say('Request failed: ' + err.message, 'error');
+                });
+            });
+
+            finishBtn.addEventListener('click', function () {
+                const pasted = codeInput.value.trim();
+                if (!pasted) {
+                    say('Paste the address your browser was redirected to.', 'error');
+                    return;
+                }
+                finishBtn.disabled = true;
+                say('Exchanging the code with Google...');
+                post({ redirect_url: pasted }).then(function (data) {
+                    finishBtn.disabled = false;
+                    if (data.status !== 'success') {
+                        say(data.message || 'Authentication failed.', 'error');
+                        return;
+                    }
+                    say(data.message || 'Authenticated.', 'success');
+                    step2.classList.add('hidden');
+                    codeInput.value = '';
+                }).catch(function (err) {
+                    finishBtn.disabled = false;
+                    say('Request failed: ' + err.message, 'error');
+                });
+            });
+
+            step2.appendChild(link);
+            step2.appendChild(hint);
+            step2.appendChild(codeLabel);
+            step2.appendChild(codeInput);
+            step2.appendChild(finishBtn);
+
+            container.appendChild(hidden);
+            container.appendChild(startBtn);
+            container.appendChild(status);
+            container.appendChild(step2);
+        },
+
+        getValue: function (fieldId) {
+            const hidden = document.getElementById(fieldId + '_hidden');
+            return hidden ? hidden.value : '';
+        }
+    });
+})();

web_interface/templates/v3/base.html

@@ -987,6 +987,7 @@
     <script src="{{ url_for('static', filename='v3/js/widgets/custom-feeds.js') }}" defer></script>
     <script src="{{ url_for('static', filename='v3/js/widgets/array-table.js') }}" defer></script>
     <script src="{{ url_for('static', filename='v3/js/widgets/google-calendar-picker.js') }}" defer></script>
+    <script src="{{ url_for('static', filename='v3/js/widgets/google-oauth.js') }}" defer></script>
     <script src="{{ url_for('static', filename='v3/js/widgets/day-selector.js') }}" defer></script>
     <script src="{{ url_for('static', filename='v3/js/widgets/time-range.js') }}" defer></script>
     <script src="{{ url_for('static', filename='v3/js/widgets/time-picker.js') }}" defer></script>

web_interface/templates/v3/partials/plugin_config.html

@@ -815,7 +815,7 @@
                     <i class="fas fa-info-circle mr-1"></i>
                     Changes in the file manager save immediately — no need to click Save Configuration.
                 </p>
-            {% elif str_widget in ['text-input', 'textarea', 'select-dropdown', 'toggle-switch', 'radio-group', 'date-picker', 'time-picker', 'slider', 'color-picker', 'email-input', 'url-input', 'password-input', 'font-selector', 'file-upload-single', 'plugin-file-manager'] %}
+            {% elif str_widget in ['text-input', 'textarea', 'select-dropdown', 'toggle-switch', 'radio-group', 'date-picker', 'time-picker', 'slider', 'color-picker', 'email-input', 'url-input', 'password-input', 'font-selector', 'file-upload-single', 'plugin-file-manager', 'google-oauth'] %}
                 {# Render widget container #}
                 <div id="{{ field_id }}_container" class="{{ str_widget }}-container"></div>
                 <script>