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/domain/entities.dart

@@ -1681,6 +1681,76 @@ final class WorkoutTelemetrySample {
   final double? caloriesKcal;
 }
 
+final class ActiveWorkoutTelemetryWindowState {
+  ActiveWorkoutTelemetryWindowState({
+    required String sessionId,
+    required this.windowStartedActiveMs,
+    required this.latestCapturedAt,
+    this.programIndex,
+    this.exerciseIndex,
+    this.setIndex,
+    this.passageIndex,
+    this.stepIndex,
+    this.programSnapshotId,
+    this.exerciseSnapshotId,
+    this.stepSnapshotId,
+    this.heartRateBpm,
+    this.distanceMeters,
+    this.caloriesKcal,
+  }) : sessionId = _nonBlank(sessionId, 'Telemetry window session id') {
+    _requireNonNegative(windowStartedActiveMs, 'Telemetry window active ms');
+    _requireNullableNonNegative(programIndex, 'Program index');
+    _requireNullableNonNegative(exerciseIndex, 'Exercise index');
+    _requireNullableNonNegative(setIndex, 'Set index');
+    _requireNullableNonNegative(passageIndex, 'Passage index');
+    _requireNullableNonNegative(stepIndex, 'Step index');
+    _requireNullablePositive(heartRateBpm, 'Heart rate bpm');
+    _requireNullableNonNegativeDouble(distanceMeters, 'Distance meters');
+    _requireNullableNonNegativeDouble(caloriesKcal, 'Calories kcal');
+    if (heartRateBpm == null &&
+        distanceMeters == null &&
+        caloriesKcal == null) {
+      throw const DomainException(
+        'Telemetry window state must contain at least one metric.',
+      );
+    }
+  }
+
+  final String sessionId;
+  final int windowStartedActiveMs;
+  final DateTime latestCapturedAt;
+  final int? programIndex;
+  final int? exerciseIndex;
+  final int? setIndex;
+  final int? passageIndex;
+  final int? stepIndex;
+  final String? programSnapshotId;
+  final String? exerciseSnapshotId;
+  final String? stepSnapshotId;
+  final int? heartRateBpm;
+  final double? distanceMeters;
+  final double? caloriesKcal;
+
+  WorkoutTelemetrySample toSample(String id) {
+    return WorkoutTelemetrySample(
+      id: id,
+      sessionId: sessionId,
+      capturedAt: latestCapturedAt,
+      programIndex: programIndex,
+      exerciseIndex: exerciseIndex,
+      setIndex: setIndex,
+      passageIndex: passageIndex,
+      stepIndex: stepIndex,
+      programSnapshotId: programSnapshotId,
+      exerciseSnapshotId: exerciseSnapshotId,
+      stepSnapshotId: stepSnapshotId,
+      heartRateBpm: heartRateBpm,
+      distanceMeters: distanceMeters,
+      caloriesKcal: caloriesKcal,
+    );
+  }
+}
+
 final class WorkoutTelemetryAggregate {
   WorkoutTelemetryAggregate({
     required String sessionId,
@@ -1793,6 +1863,51 @@ final class WorkoutTelemetryGraphSeries {
   final int? maxHeartRateBpm;
 }
 
+final class ScopeInstanceDescriptor {
+  ScopeInstanceDescriptor({
+    required this.scope,
+    this.programIndex,
+    this.exerciseIndex,
+    this.setIndex,
+    this.passageIndex,
+    this.stepIndex,
+    required this.ordinal,
+    required DateTime firstCapturedAt,
+  }) : firstCapturedAt = firstCapturedAt.toUtc() {
+    _requireNullableNonNegative(programIndex, 'Program index');
+    _requireNullableNonNegative(exerciseIndex, 'Exercise index');
+    _requireNullableNonNegative(setIndex, 'Set index');
+    _requireNullableNonNegative(passageIndex, 'Passage index');
+    _requireNullableNonNegative(stepIndex, 'Step index');
+    _requirePositive(ordinal, 'Scope instance ordinal');
+  }
+
+  final WorkoutTelemetryAggregateScope scope;
+  final int? programIndex;
+  final int? exerciseIndex;
+  final int? setIndex;
+  final int? passageIndex;
+  final int? stepIndex;
+  final int ordinal;
+  final DateTime firstCapturedAt;
+}
+
+enum ScopeMarkerBoundary { start, end }
+
+final class ScopeMarker {
+  ScopeMarker({
+    required this.elapsedMs,
+    required String label,
+    required this.boundary,
+  }) : label = _nonBlank(label, 'Scope marker label') {
+    _requireNonNegative(elapsedMs, 'Scope marker elapsed ms');
+  }
+
+  final int elapsedMs;
+  final String label;
+  final ScopeMarkerBoundary boundary;
+}
+
 final class WorkoutHistorySetResult {
   WorkoutHistorySetResult({
     required this.metadata,