fix(online): validation client online offline-first (ticket #70)

Corrige l'acceptation de partage hors-ligne (acceptShare,
_acceptCachedShareAndQueueAck, _importSharedPayload dans
application/use_cases.dart) : crée bien une copie locale indépendante
avec de nouveaux IDs avant de mettre l'accusé serveur en file
d'attente. Ajuste app_bootstrap.dart, profile_screen.dart et
share_screen.dart en conséquence. flutter pub get OK, dart format
appliqué (aucun changement), analyze propre (mêmes infos
préexistantes), 137/137 tests verts, build APK debug validé. Dernier
ticket du chantier "Ajouter les features serveur au client" (#63,
tickets #64 à #70 tous terminés).

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

test/application/use_cases_test.dart

@@ -1434,6 +1434,50 @@ void main() {
     expect(inboxRepository.items.single.status, ShareInboxStatus.accepted);
   });
 
+  test(
+    'ShareUseCases acceptShare sans token importe une copie locale indépendante',
+    () async {
+      final remoteShareApi = _FakeRemoteShareApi();
+      final pendingRepository = _FakePendingShareActionRepository();
+      final programRepository = _FakeProgramRepository();
+      final inboxRepository = _FakeShareInboxRepository()
+        ..items.add(
+          _shareInboxItem(
+            status: ShareInboxStatus.pending,
+            payloadJson: jsonEncode(_sharedProgramPayload()),
+          ),
+        );
+
+      await _shareUseCase(
+        tokenStore: _FakeAuthTokenStore(),
+        remoteShareApi: remoteShareApi,
+        inboxRepository: inboxRepository,
+        pendingActionRepository: pendingRepository,
+        programRepository: programRepository,
+      ).acceptShare('share-1');
+
+      expect(remoteShareApi.acceptCalls, 0);
+      expect(
+        pendingRepository.actions.single.actionType,
+        PendingShareActionType.accept,
+      );
+      expect(inboxRepository.items.single.status, ShareInboxStatus.accepted);
+      final imported = programRepository.programs.single;
+      expect(imported.metadata.id, isNot('program-from-sender'));
+      expect(imported.metadata.originDeviceId, 'device-1');
+      expect(imported.name, 'Programme partagé');
+      expect(
+        imported.exercises.single.metadata.id,
+        isNot('exercise-from-sender'),
+      );
+      expect(imported.exercises.single.sourceExerciseId, isNull);
+      expect(
+        imported.exercises.single.exerciseStepsSnapshot.single.name,
+        'Sprint',
+      );
+    },
+  );
+
   test('ShareUseCases refreshInbox updates the local cache', () async {
     final remoteShareApi = _FakeRemoteShareApi()
       ..inboxItems = [_shareInboxItem(status: ShareInboxStatus.pending)];
@@ -1866,6 +1910,7 @@ ShareUseCases _shareUseCase({
     templateRepository: templateRepository ?? _FakeWorkoutTemplateRepository(),
     clock: _FakeClock(DateTime.utc(2026, 7, 17, 12)),
     ids: _FakeIds(),
+    originDeviceId: 'device-1',
   );
 }
 
@@ -2027,17 +2072,58 @@ Program _shareableProgram() {
 ShareInboxItem _shareInboxItem({
   String shareId = 'share-1',
   required ShareInboxStatus status,
+  String payloadJson = '{"name":"Programme partagé"}',
 }) {
   return ShareInboxItem(
     shareId: shareId,
     senderUserId: 'sender-1',
     resourceType: ShareResourceType.program,
-    payloadJson: '{"name":"Programme partagé"}',
+    payloadJson: payloadJson,
     status: status,
     createdAt: DateTime.utc(2026, 7, 17, 12),
   );
 }
 
+Map<String, Object?> _sharedProgramPayload() {
+  return {
+    'id': 'program-from-sender',
+    'name': 'Programme partagé',
+    'defaultRestSeconds': 45,
+    'exercises': [
+      {
+        'id': 'exercise-from-sender',
+        'sourceExerciseId': 'source-exercise-from-sender',
+        'position': 0,
+        'exerciseNameSnapshot': 'Sprint',
+        'exerciseStepsSnapshot': [
+          {
+            'id': 'step-from-sender',
+            'position': 0,
+            'name': 'Sprint',
+            'type': 'time',
+            'defaultTargetValue': 20,
+            'hasScore': false,
+            'scoreInputMode': 'manual',
+            'scoreLabel': null,
+            'scoreUnit': null,
+            'defaultTargetScore': null,
+            'defaultTargetScoreTimeMs': null,
+          },
+        ],
+        'availableTimeSnapshot': true,
+        'availableRepsSnapshot': false,
+        'availableScoreSnapshot': false,
+        'scoreInputModeSnapshot': 'manual',
+        'setsCount': 2,
+        'timeEnabled': true,
+        'repsEnabled': false,
+        'scoreEnabled': false,
+        'targetTimeSeconds': 20,
+      },
+    ],
+  };
+}
+
 RemoteSyncedItem _remoteSharedProgramItem() {
   return RemoteSyncedItem(
     resourceType: SyncResourceType.program,