Stabilize iOS/watchOS/tvOS apps and add cross-platform audit remediation

docs/step8_performance_state_round1.md

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+# Step 8 Performance/State Round 1
+
+## Coverage
+
+- Reviewed and patched:
+  - `iphone/Werkout_ios/DataStore.swift`
+  - `iphone/Werkout_ios/Views/WorkoutDetail/WorkoutDetailView.swift`
+  - `iphone/Werkout_ios/Views/WorkoutDetail/ExerciseListView.swift`
+  - `WekoutThotViewer/WekoutThotViewer/ContentView.swift`
+  - `iphone/Werkout_ios/BridgeModule.swift`
+  - `iphone/Werkout_ios/BridgeModule+Watch.swift`
+  - `iphone/Werkout_ios/BridgeModule+Timer.swift`
+  - `iphone/Werkout_watch Watch App/WatchWorkout.swift`
+- Validation run:
+  - `./scripts/smoke/smoke_all.sh`
+
+## Fixes
+
+1. Coalesced concurrent `fetchAllData` requests
+   - `DataStore` now queues completion handlers while a fetch is active to prevent overlapping network fan-out and state churn.
+
+2. Reduced AVPlayer churn in iOS workout detail
+   - Reuses current player for same URL by seeking to start instead of recreating `AVPlayer` each time exercise/video updates.
+
+3. Reduced AVPlayer churn in iOS exercise preview sheet
+   - Added preview URL tracking; same URL now replays without allocating a new player.
+
+4. Reduced AVPlayer churn in tvOS content loop
+   - Same URL replay now seeks/replays existing player rather than recreating.
+
+5. Capped queued watch messages on iOS bridge
+   - Added queue cap to prevent unbounded growth while watch is disconnected.
+
+6. Added queue fallback for send failures
+   - Failed reachable send now re-queues payload for later delivery.
+
+7. Improved timer power behavior
+   - Added timer tolerance to workout/exercise timers.
+
+8. Fixed watch heart-rate loop early-return behavior
+   - Non-heart sample types now `continue` instead of exiting handler early.
+
+## Validation
+
+- Smoke suite passed:
+  - token scan
+  - SharedCore tests
+  - iOS/watchOS/tvOS builds