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/Views/WorkoutLogs/WorkoutLogsView.swift

@@ -88,6 +88,7 @@ struct WorkoutLogsView: View {
                         withAnimation {
                             viewContext.delete(item)
                             try? viewContext.save()
+                            WatchConnectivityManager.shared.syncAllData()
                             itemToDelete = nil
                         }
                     }
@@ -167,11 +168,17 @@ struct SplitPickerSheet: View {
             workoutLog.sets = exercise.sets
             workoutLog.reps = exercise.reps
             workoutLog.weight = exercise.weight
+            workoutLog.loadType = exercise.loadType
+            workoutLog.duration = exercise.duration
             workoutLog.status = .notStarted
             workoutLog.workout = workout
         }
 
         try? viewContext.save()
+
+        // Sync to Watch
+        WatchConnectivityManager.shared.syncAllData()
+
         dismiss()
     }
 }