feat(watch): clôture lot #91 - fréquence cardiaque live, notifications de séance et finitions montre

Consolide le lot applicatif watch companion validé :
- télémétrie fréquence cardiaque live remontée montre -> téléphone
  (collecteur watch, adapter Wear Data Layer, persistance Drift,
  propagation aux écrans historique/programme/profil/exécution)
- notifications de séance en arrière-plan côté téléphone (service
  foreground de statut + passerelle applicative)
- finitions montre : chrono d'étape, score d'étape, retrait du bouton
  "lancer une séance", thème, icônes et polices watch_app

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

packages/watch_bridge_contract/test/watch_bridge_contract_test.dart

@@ -52,6 +52,94 @@ void main() {
     });
   });
 
+  group('WatchSensorSummary', () {
+    test('round-trips heart rate summary through JSON', () {
+      const summary = WatchSensorSummary(
+        sessionId: 'session-1',
+        sampleCount: 12,
+        minHeartRateBpm: 91,
+        averageHeartRateBpm: 128.5,
+        maxHeartRateBpm: 174,
+        totalDistanceMeters: 842.4,
+        totalCaloriesKcal: 186.2,
+      );
+
+      final decoded = WatchSensorSummary.fromJson(
+        jsonDecode(jsonEncode(summary.toJson())) as Map<String, Object?>,
+      );
+
+      expect(decoded, summary);
+    });
+
+    test('falls back safely for absent fields', () {
+      final summary = WatchSensorSummary.fromJson({});
+
+      expect(summary.schemaVersion, watchBridgeSchemaVersion);
+      expect(summary.sessionId, '');
+      expect(summary.sampleCount, 0);
+      expect(summary.minHeartRateBpm, isNull);
+      expect(summary.averageHeartRateBpm, isNull);
+      expect(summary.maxHeartRateBpm, isNull);
+      expect(summary.totalDistanceMeters, isNull);
+      expect(summary.totalCaloriesKcal, isNull);
+    });
+  });
+
+  group('WatchSensorSample', () {
+    test('round-trips live telemetry sample through JSON', () {
+      const sample = WatchSensorSample(
+        sampleId: 'sample-1',
+        sessionId: 'session-1',
+        capturedAtEpochMs: 1710000000300,
+        programIndex: 0,
+        exerciseIndex: 1,
+        setIndex: 2,
+        passageIndex: 3,
+        stepIndex: 4,
+        programSnapshotId: 'program-snapshot-1',
+        exerciseSnapshotId: 'exercise-snapshot-1',
+        stepSnapshotId: 'step-snapshot-1',
+        heartRateBpm: 142,
+        distanceMeters: 840.5,
+        caloriesKcal: 184.2,
+      );
+
+      final decoded = WatchSensorSample.fromJson(
+        jsonDecode(jsonEncode(sample.toJson())) as Map<String, Object?>,
+      );
+
+      expect(decoded, sample);
+    });
+
+    test('falls back safely for absent fields', () {
+      final sample = WatchSensorSample.fromJson({});
+
+      expect(sample.schemaVersion, watchBridgeSchemaVersion);
+      expect(sample.sampleId, isNull);
+      expect(sample.sessionId, '');
+      expect(sample.recordedAtEpochMs, 0);
+      expect(sample.capturedAtEpochMs, 0);
+      expect(sample.programIndex, isNull);
+      expect(sample.exerciseIndex, isNull);
+      expect(sample.setIndex, isNull);
+      expect(sample.passageIndex, isNull);
+      expect(sample.stepIndex, isNull);
+      expect(sample.heartRateBpm, isNull);
+      expect(sample.distanceMeters, isNull);
+      expect(sample.caloriesKcal, isNull);
+    });
+
+    test('accepts legacy recordedAtEpochMs as captured timestamp', () {
+      final sample = WatchSensorSample.fromJson({
+        'sessionId': 'session-1',
+        'recordedAtEpochMs': 1710000000300,
+      });
+
+      expect(sample.capturedAtEpochMs, 1710000000300);
+      expect(sample.recordedAtEpochMs, 1710000000300);
+    });
+  });
+
   group('WatchSessionProjection', () {
     test('round-trips every phase, primary action, and secondary action', () {
       for (final phase in WatchSessionPhase.values) {
@@ -65,6 +153,9 @@ void main() {
             seriesIndex: 2,
             seriesTotal: 5,
             exerciseName: 'Pompes tempo',
+            programIndex: 0,
+            exerciseIndex: 1,
+            setIndex: 1,
             passageIndex: 1,
             passageTotal: 3,
             stepIndex: 2,
@@ -76,6 +167,12 @@ void main() {
             secondaryActions: WatchSecondaryAction.values,
             nextExerciseName: 'Fentes sautees',
             statusLabel: 'Chrono etape',
+            hasManualScore: true,
+            currentManualScoreValue: 7.5,
+            canDecrementScore: true,
+            manualScoreTargetValue: 10,
+            manualScoreTargetLabel: 'Cible',
+            manualScoreScope: WatchManualScoreScope.step,
           );
 
           final decoded = WatchSessionProjection.fromJson(
@@ -114,6 +211,12 @@ void main() {
       ]);
       expect(projection.nextExerciseName, isNull);
       expect(projection.statusLabel, isNull);
+      expect(projection.hasManualScore, isFalse);
+      expect(projection.currentManualScoreValue, isNull);
+      expect(projection.canDecrementScore, isFalse);
+      expect(projection.manualScoreTargetValue, isNull);
+      expect(projection.manualScoreTargetLabel, isNull);
+      expect(projection.manualScoreScope, isNull);
     });
 
     test('falls back to neutral values for absent required fields', () {
@@ -130,6 +233,12 @@ void main() {
       expect(projection.exerciseName, '');
       expect(projection.primaryAction, WatchPrimaryAction.none);
       expect(projection.secondaryActions, isEmpty);
+      expect(projection.hasManualScore, isFalse);
+      expect(projection.currentManualScoreValue, isNull);
+      expect(projection.canDecrementScore, isFalse);
+      expect(projection.manualScoreTargetValue, isNull);
+      expect(projection.manualScoreTargetLabel, isNull);
+      expect(projection.manualScoreScope, isNull);
     });
   });