Stage 4: guided Player for both Modes and the Session summary

- buildSegments lays a Plan out as holds with Transitions (get ready,
  switch sides, next round, next exercise) or sets with count-up Rests;
  Supersets alternate members and rest per round unless asked otherwise
- SessionRunner drives segments against an injected clock: auto-advance
  with a chime, pause, skip, back, rep sets confirmed with logged reps
  and kg, timed sets started on demand, early end
- Player screen: countdown ring, accent pulse in the last 3 s, Flip
  Animation, next-up cards, Rest Screen, mute toggle, screen kept on
- Sessions table (schema v2 migration) keeps a Plan snapshot and Set
  Logs; nothing is saved when no hold or set was done
- Summary with time, exercises or sets logged, and every Set Log
- Synthesised quiet cue sounds (tools/sounds), status bar per Mode

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

lib/main.dart

@@ -6,7 +6,9 @@ import 'package:provider/provider.dart';
 import 'src/app.dart';
 import 'src/database/database.dart';
 import 'src/exercises/exercise_library.dart';
+import 'src/history/session_repository.dart';
 import 'src/plans/plan_repository.dart';
+import 'src/player/player_effects.dart';
 import 'src/settings/settings_controller.dart';
 
 void main() async {
@@ -24,6 +26,8 @@ void main() async {
         ChangeNotifierProvider.value(value: settings),
         Provider.value(value: library),
         Provider.value(value: PlanRepository(db)),
+        Provider.value(value: SessionRepository(db)),
+        Provider<PlayerEffects>(create: (_) => DevicePlayerEffects()),
       ],
       child: const ZenXerciseApp(),
     ),