Make Apple Health workout recording watch-only

The phone no longer writes estimated Health workouts: the watch, which
runs the live session, is the sole recorder. Replaces WorkoutHealthWriter
with a WorkoutHealthDeleter that only removes a legacy phone-estimate
workout when its record is deleted here, drops the MET calorie table and
the phone's write/read Health scopes, and keeps phoneEstimate decodable
for existing documents.

Claude-Session: https://claude.ai/code/session_01HJDQQDA9QdP8zByg43H5v3

Workouts/AppServices.swift

@@ -12,7 +12,7 @@ final class AppServices {
     let syncEngine: SyncEngine
     let watchBridge: PhoneConnectivityBridge
     let workoutLauncher = WorkoutLauncher()
-    let workoutHealthWriter: WorkoutHealthWriter
+    let workoutHealthDeleter = WorkoutHealthDeleter()
 
     /// Ephemeral live-run state fed by the watch, observed by the mirror UI. Not persisted.
     let liveRunState: LiveRunState
@@ -26,10 +26,6 @@ final class AppServices {
         let liveRunState = LiveRunState()
         self.liveRunState = liveRunState
         self.watchBridge = PhoneConnectivityBridge(container: container, syncEngine: syncEngine, liveRunState: liveRunState)
-        let writer = WorkoutHealthWriter(container: container, syncEngine: syncEngine)
-        self.workoutHealthWriter = writer
-        syncEngine.onWorkoutCompleted = { [weak writer] doc in writer?.workoutCompleted(doc) }
-        syncEngine.onWatchMetricsArrived = { [weak writer] id in writer?.watchMetricsArrived(workoutID: id) }
         #if DEBUG
         if ScreenshotSeed.isActive { ScreenshotSeed.populate(container.mainContext) }
         #endif
@@ -43,10 +39,9 @@ final class AppServices {
             guard let self else { return }
             await self.syncEngine.connect()
             self.watchBridge.activate()
-            // Past the iCloud gate and cache is reconciled: request Health access and
-            // back-fill any recently-completed workout that never reached Health.
-            self.workoutHealthWriter.authorizeIfNeeded()
-            self.workoutHealthWriter.sweepRecentlyCompleted()
+            // Past the iCloud gate: request the workout-share scope so the user can still
+            // delete legacy phone-estimate workouts from Health when deleting them here.
+            self.workoutHealthDeleter.authorizeIfNeeded()
         }
         bootstrapTask = task
         await task.value