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>

lib/infrastructure/local/app_database.dart

@@ -9,6 +9,7 @@ part 'app_database.g.dart';
   tables: [
     ActiveExerciseStepProgressStates,
     ActiveExerciseStepResults,
+    ActiveWorkoutTelemetryWindowStates,
     ActiveRestStates,
     ActiveManualScoreStates,
     ActiveScoreStopwatchStates,
@@ -51,7 +52,7 @@ final class AppDatabase extends _$AppDatabase {
   }
 
   @override
-  int get schemaVersion => 25;
+  int get schemaVersion => 26;
 
   @override
   MigrationStrategy get migration {
@@ -141,6 +142,9 @@ final class AppDatabase extends _$AppDatabase {
         if (from < 25) {
           await _migrateToSchema25();
         }
+        if (from < 26) {
+          await _migrateToSchema26(migrator);
+        }
         await _createIndexes();
       },
       beforeOpen: (details) async {
@@ -269,6 +273,11 @@ final class AppDatabase extends _$AppDatabase {
       'CREATE INDEX IF NOT EXISTS idx_workout_telemetry_samples_session '
       'ON workout_telemetry_samples (session_id, captured_at)',
     );
+    await customStatement(
+      'CREATE INDEX IF NOT EXISTS '
+      'idx_active_workout_telemetry_window_states_session '
+      'ON active_workout_telemetry_window_states (session_id)',
+    );
     await customStatement(
       'CREATE INDEX IF NOT EXISTS idx_workout_telemetry_aggregates_session '
       'ON workout_telemetry_aggregates (session_id, scope)',
@@ -472,6 +481,10 @@ extension on AppDatabase {
     await migrator.createTable(pendingShareActions);
   }
 
+  Future<void> _migrateToSchema26(Migrator migrator) async {
+    await migrator.createTable(activeWorkoutTelemetryWindowStates);
+  }
+
   Future<void> _migrateToSchema13() async {
     await customStatement('PRAGMA foreign_keys = OFF');
     await customStatement('''