Preserve loader behavior while reducing hidden work (#1996)

* fix(app): preserve loader behavior in retained panels

Keep the running footer mounted across panel switches. Inactive loaders stop their animation work, then realign to the original wall-clock phase before they become visible.

* perf(app): remove inactive loader wrapper worklet

* perf(app): pause hidden turn elapsed timers

* perf(app): reduce loader animation work

Keep one wall-clock-aligned clock for visible loaders and detach retained
hidden loaders without unmounting them. Preserve the 950 ms sequence and
reduced-motion behavior.

docs/coding-standards.md

@@ -87,7 +87,7 @@ For testing rules, see [testing.md](testing.md).
 - Collection rows do not independently subscribe to a high-frequency global store. The collection owner selects structurally shared indexes once, derives a keyed row model with `useMemo`, and passes entries to rows. This keeps retained hidden collections current without running one selector per row on every store update.
 - Equality functions prevent React renders; they do not prevent selector callbacks from running. A selector attached to a hot store must be O(1) when its relevant source references have not changed.
 - Retained native panels use `RetainedPanel`. If an existing gesture/layout wrapper must own visibility, wrap its contents in `RetainedPanelActivity` instead. Keep keyed panel roots in a stable sibling order, include the newly active panel in the same render, centralize subscriptions, and gate genuine effects through `useRetainedPanelActive`. Do not use `Suspense` or render freezing for this on native: those techniques change native tree ownership instead of merely stopping work.
-- Infinite animations are subscriptions. Start them only while their retained panel is active, and cancel a shared clock when its final active consumer leaves. Match scheduler cadence to the actual visual cadence; do not run a 60 fps interpolation when the rendered value changes only a few times per second.
+- Infinite animations are subscriptions. Start them only while their retained panel is active, and cancel a shared clock when its final active consumer leaves. Synchronized animations use one clock per animation family and feed active instances through local shared values; retained hidden instances stay mounted but unsubscribed. Match state updates to the actual visual cadence; do not run every style worklet at 60 fps when the rendered value changes only a few times per second.
 - Stable references for props that cross `memo` boundaries or feed dependency arrays. Static literals at module scope `as const`; derived with `useMemo`; handlers with `useCallback` only when there's a memoized beneficiary.
 - Use stable ids for `key`, never array index for reorderable/filterable lists.
 - Context for stable values (theme, auth). Store with selectors for state that changes.

docs/mobile-panels.md

@@ -85,6 +85,9 @@ definition, no longer eligible to begin.
 - Panels whose gesture wrapper already owns visibility use `RetainedPanelActivity` to provide the
   same active signal without adding another layout root. Persistent animations, timers, polling, and
   shared clocks must subscribe to that signal and stop when their final visible consumer leaves.
+- Synchronized step animations use one wall-clock-aligned source. Register a local shared value only
+  while its retained panel is active so hidden animated styles remain mounted without receiving clock
+  updates. Do not give every instance its own loop or leave hidden styles subscribed to the source.
 - Retention order and render order are separate concerns. LRU metadata may change on every switch;
   keyed retained roots must keep a stable sibling order. Moving large retained roots triggered Fabric
   Differ failures (`addViewAt` / `removeViewAt` view reuse) on Android.