fix(watch): retablit la remontee distance/calories Health Services

Corrige l'absence de distance/calories alors que la FC fonctionnait. Perimetre QA vert cible, sans changement UI.

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

packages/watch_bridge_contract/test/watch_bridge_contract_test.dart

@@ -132,6 +132,21 @@ void main() {
       expect(summary.totalDistanceMeters, isNull);
       expect(summary.totalCaloriesKcal, isNull);
     });
+
+    test('accepts legacy live metric keys for summary totals', () {
+      final summary = WatchSensorSummary.fromJson({
+        'sessionId': 'session-1',
+        'sampleCount': 4,
+        'minHeartRateBpm': 91,
+        'averageHeartRateBpm': 128.5,
+        'maxHeartRateBpm': 174,
+        'distanceMeters': 842.4,
+        'caloriesKcal': 186.2,
+      });
+
+      expect(summary.totalDistanceMeters, 842.4);
+      expect(summary.totalCaloriesKcal, 186.2);
+    });
   });
 
   group('WatchSensorSample', () {