fix(plugins): let a plugin ask to be polled faster while it has live content

Reported: "the football plugin with live games only updates the live game in
progress if I restart the display."

The data path was never the problem. NFLLiveManager fetches ESPN with no cache,
SportsLive.update() refreshes current_game in place when the game IDs are
unchanged, and the scorebug redraws from the game dict every frame -- which is
why the reporter's logs look healthy.

The problem is cadence. _get_plugin_update_interval() read only the manifest's
static update_interval, football's manifest pins that to 60, and the plugin's
own live_update_interval (15s) was invisible to the scheduler. Measured on a rig
during the fourth quarter of the game in the report:

    23:21:49  23:22:50  23:23:50  23:24:50  23:25:50   <- exactly 60s apart

A clock and score up to a minute stale during a two-minute drill reads as a
frozen panel, and a restart is the one moment it is ever current.

A single static number cannot say "every 15 seconds while a game is on, every 15
minutes in July", and only the plugin knows which is true. get_update_interval()
lets it say so per tick; returning None means "no opinion" and the existing
manifest/config resolution applies, so every plugin that predates this is
unaffected.

Requests are clamped to MIN_DYNAMIC_UPDATE_INTERVAL (5s): a plugin returning 0
would otherwise be re-entered on every tick of the render loop, busy-waiting
against its own API. A hook that raises or returns a non-number is ignored
rather than propagated -- a scheduler that fails on one plugin's bug stops
updating all the others.

Deliberately NOT changed: the manifest still beats config in the static path.
That looked like the obvious fix -- user config being silently ignored -- until
checking a real rig, where football and baseball both carry update_interval 3600
in config against a manifest 60, and weather 1800 against 60. Those values are
stale precisely because nothing has been honouring them; making config win would
have slowed three plugins by 60x, turning a one-minute lag into an hour. The
dynamic hook makes the flip unnecessary. There is a test pinning the current
precedence with that reasoning attached.

Full suite: 4,283 passed, 68 skipped.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014RRtqXDCnvnY6EQwhT5CV9

src/plugin_system/base_plugin.py

@@ -520,6 +520,38 @@ class BasePlugin(ABC):
         """
         return
 
+    def get_update_interval(self) -> Optional[float]:
+        """
+        How often this plugin wants update() called, right now, in seconds.
+
+        The manifest's ``update_interval`` is a single static number, which
+        cannot say "poll me every 15 seconds while a game is in progress and
+        every 15 minutes when nothing is on". Only the plugin knows which is
+        true at any moment, so override this to say so.
+
+        Return None (the default) to accept the manifest/config value.
+
+        Two constraints, both because the scheduler calls this on every tick of
+        the render loop:
+
+        - It must be cheap. Attribute reads only -- no config lookups, no I/O,
+          no locks that a fetch might be holding.
+        - It must not raise. A raising hook is ignored and the static interval
+          used, but a hook that raises every tick also logs every tick.
+
+        Values below PluginManager.MIN_DYNAMIC_UPDATE_INTERVAL are clamped up:
+        a plugin asking for 0 would otherwise busy-wait against its own API.
+
+        Example::
+
+            def get_update_interval(self):
+                # Fast while something is actually live, manifest default otherwise.
+                if any(m.live_games for m in self._live_managers):
+                    return self.config.get("live_update_interval", 15)
+                return None
+        """
+        return None
+
     def has_live_priority(self) -> bool:
         """
         Check if this plugin has live priority enabled.

src/plugin_system/plugin_manager.py

@@ -779,15 +779,63 @@ class PluginManager:
 
         return None
 
+    def _dynamic_update_interval(self, plugin_id: str, plugin_instance: Any) -> Optional[float]:
+        """The interval a plugin asks for right now, or None if it has no view."""
+        hook = getattr(plugin_instance, 'get_update_interval', None)
+        if not callable(hook):
+            return None
+        try:
+            requested = hook()
+        except Exception as exc:  # pylint: disable=broad-except
+            self.logger.debug(
+                "get_update_interval() failed for %s, using the static interval: %s",
+                plugin_id, exc)
+            return None
+        if requested is None:
+            return None
+        try:
+            requested = float(requested)
+        except (TypeError, ValueError):
+            self.logger.debug(
+                "get_update_interval() returned %r for %s, which is not a number",
+                requested, plugin_id)
+            return None
+        if requested != requested or requested == float('inf'):  # NaN / inf
+            return None
+        return max(requested, self.MIN_DYNAMIC_UPDATE_INTERVAL)
+
+    #: Floor for a plugin-requested interval. A plugin asking for 0 (or a
+    #: negative) would otherwise be re-entered on every tick of the render
+    #: loop, which is a busy-wait against whatever API it fetches.
+    MIN_DYNAMIC_UPDATE_INTERVAL = 5.0
+
     def _get_plugin_update_interval(self, plugin_id: str, plugin_instance: Any) -> Optional[float]:
         """
         Get the data-fetch interval for a plugin (seconds between update() calls).
 
-        Result is cached per plugin_id after the first lookup to avoid calling
-        config_manager.get_config() — which returns a full dict copy — on every
-        tick of the 30-fps display loop.  The cache is invalidated when a plugin
-        is loaded or unloaded.
+        A plugin may implement ``get_update_interval()`` to vary its own cadence
+        at runtime, which the static manifest value cannot express. The case
+        this exists for: a sports scoreboard needs to poll every 15s while a
+        game is in progress and every 15 minutes when nothing is on, and only
+        the plugin knows which is true right now. Returning None from the hook
+        means "no opinion", and the static resolution below applies.
+
+        The hook is called on every scheduling tick, so implementations must be
+        cheap — attribute reads, no config lookups and no I/O. A raising or
+        non-numeric hook is ignored rather than allowed to stop the plugin
+        updating, since a scheduler that propagates a plugin bug stops every
+        other plugin too.
+
+        The static result is cached per plugin_id after the first lookup to
+        avoid calling config_manager.get_config() — which returns a full dict
+        copy — on every tick of the 30-fps display loop. The cache is
+        invalidated when a plugin is loaded or unloaded. The dynamic hook is
+        deliberately *not* cached: caching it would defeat its only purpose.
         """
+        dynamic = self._dynamic_update_interval(plugin_id, plugin_instance)
+        if dynamic is not None:
+            return dynamic
+
         if plugin_id in self._update_interval_cache:
             return self._update_interval_cache[plugin_id]