Consolidate extension data providers and add side effects catch-up

- Create unified ExtensionDataProvider for Widget and Watch targets
- Remove duplicate WatchDataProvider and WatchConnectivityManager from Watch App
- Add side effects catch-up mechanism in MoodLogger for widget votes
- Process pending side effects on app launch and midnight background task
- Reduce ~450 lines of duplicated code across targets

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Shared/FeelsApp.swift

@@ -69,7 +69,7 @@ struct FeelsApp: App {
             }
         }.onChange(of: scenePhase) { _, newPhase in
             if newPhase == .background {
-                //BGTask.scheduleBackgroundProcessing()
+                BGTask.scheduleBackgroundProcessing()
                 WidgetCenter.shared.reloadAllTimelines()
                 // Lock the app when going to background
                 authManager.lock()
@@ -89,6 +89,9 @@ struct FeelsApp: App {
                 }
                 // Reschedule Live Activity when app becomes active
                 LiveActivityScheduler.shared.scheduleBasedOnCurrentTime()
+
+                // Catch up on side effects from widget/watch votes
+                MoodLogger.shared.processPendingSideEffects()
             }
         }
     }