Add WatchConnectivity for bidirectional iOS-Watch sync

Implement real-time sync between iOS and Apple Watch apps using
WatchConnectivity framework. This replaces reliance on CloudKit
which doesn't work reliably in simulators.

- Add WatchConnectivityManager to both iOS and Watch targets
- Sync workouts, splits, exercises, and logs between devices
- Update iOS views to trigger sync on data changes
- Add onChange observer to ExerciseView for live progress updates
- Configure App Groups for shared container storage
- Add Watch app views: WorkoutLogsView, WorkoutLogListView, ExerciseProgressView

Workouts/Workouts.entitlements

@@ -14,5 +14,9 @@
 	</array>
 	<key>com.apple.developer.ubiquity-kvstore-identifier</key>
 	<string>$(TeamIdentifierPrefix)$(CFBundleIdentifier)</string>
+	<key>com.apple.security.application-groups</key>
+	<array>
+		<string>group.dev.rzen.indie.Workouts</string>
+	</array>
 </dict>
 </plist>