Restructure into a three-tab app with Progress, goals, and Meditation

The UX redesign's first landing (spec in UX-REDESIGN.md): ContentView
becomes a Today / Progress / Settings TabView, "Routine" replaces
"Split" in every user-facing string and view name (code-level types
keep their names), and workout starting moves to shared
WorkoutStarter / StartedWorkoutNavigator plumbing.

- New Progress tab: weekly goal streaks, workout trends, per-exercise
  weight progression, achievements, and the full history list
  (WorkoutLogsView -> WorkoutHistoryView).
- Goals: stable categories workouts roll up to, managed from Settings.
- New Meditation exercise + starter routine; timed sits record to
  Apple Health as Mind & Body sessions.

Claude-Session: https://claude.ai/code/session_012qw2itfzKyEJ1HpsFt8Ex4

Workouts/AppServices.swift

@@ -43,6 +43,18 @@ final class AppServices {
         let liveRunState = LiveRunState()
         self.liveRunState = liveRunState
         self.watchBridge = PhoneConnectivityBridge(container: container, syncEngine: syncEngine, liveRunState: liveRunState)
+        // Launch the wrist session only when a run actually begins (the first
+        // exercise leaves `.notStarted` on the phone) — creating a workout alone is
+        // just a peek and must not start anything on the watch. Watch-originated
+        // starts don't fire this hook; the watch already owns its session.
+        syncEngine.onWorkoutBecameActive = { [weak self] doc in
+            guard let self else { return }
+            let routine = doc.routineID.flatMap { id in
+                CacheMapper.fetchRoutine(id: syncEngine.currentRoutineID(for: id), in: container.mainContext)
+            }
+            let activityType = routine?.activityTypeEnum ?? .traditionalStrength
+            self.workoutLauncher.launchWatchWorkout(activityType: activityType.hkActivityType)
+        }
         #if DEBUG
         if ScreenshotSeed.isActive { ScreenshotSeed.populate(container.mainContext) }
         #endif