feat(server): implemente synchronisation et serveur avec fixtures (#187)

- Implémente la couche de synchronisation avec le serveur
- Ajoute les fixtures versionnées pour les tests
- Met à jour Drift database et repositories pour le support sync
- Améliore les tests de synchronisation
- Corrige et améliore le watch companion pour la collecte de métriques

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

test/infrastructure/watch_bridge/wear_data_layer_adapter_test.dart

@@ -5,6 +5,7 @@ import 'package:gametime/application/application.dart';
 import 'package:gametime/domain/domain.dart';
 import 'package:gametime/infrastructure/infrastructure.dart'
     hide
+        ActiveWorkoutTelemetryWindowState,
         WorkoutHistory,
         WorkoutHistorySetResult,
         WorkoutHistoryStepResult,
@@ -311,6 +312,25 @@ void main() {
       ),
     );
     await Future<void>.delayed(Duration.zero);
+    expect(telemetryRepository.samples, isEmpty);
+
+    native.emitSensorSample(
+      WatchSensorSample(
+        sampleId: 'sample-2',
+        sessionId: 'session-1',
+        recordedAtEpochMs: _now
+            .add(const Duration(seconds: 20))
+            .millisecondsSinceEpoch,
+        programIndex: 0,
+        exerciseIndex: 0,
+        setIndex: 0,
+        stepIndex: 0,
+        heartRateBpm: 130,
+        distanceMeters: 520,
+        caloriesKcal: 45,
+      ),
+    );
+    await Future<void>.delayed(Duration.zero);
 
     expect(
       telemetryRepository.samples.single.id,
@@ -658,6 +678,7 @@ final class _FakeWorkoutTelemetryRepository
     implements WorkoutTelemetryRepository {
   final samples = <WorkoutTelemetrySample>[];
   final aggregates = <WorkoutTelemetryAggregate>[];
+  final windowStates = <String, ActiveWorkoutTelemetryWindowState>{};
 
   @override
   Future<bool> saveSample(WorkoutTelemetrySample sample) async {
@@ -668,6 +689,23 @@ final class _FakeWorkoutTelemetryRepository
     return true;
   }
 
+  @override
+  Future<ActiveWorkoutTelemetryWindowState?> findWindowState(
+    String sessionId,
+  ) async {
+    return windowStates[sessionId];
+  }
+
+  @override
+  Future<void> saveWindowState(ActiveWorkoutTelemetryWindowState state) async {
+    windowStates[state.sessionId] = state;
+  }
+
+  @override
+  Future<void> deleteWindowState(String sessionId) async {
+    windowStates.remove(sessionId);
+  }
+
   @override
   Future<List<WorkoutTelemetrySample>> listSamples(String sessionId) async {
     return samples