feat(online): partage client - use cases, inbox cache et import local (ticket #66)

Ajoute l'adapter API distant de partage (infrastructure/remote/share_api.dart)
et les use cases associés (application/use_cases.dart), avec cache
d'inbox et import local des ressources partagées acceptées. Étend le
modèle Drift (migration schemaVersion 11→12) et les entités du domaine
en conséquence. flutter pub get OK, build_runner OK, dart format
appliqué, analyze propre (mêmes infos préexistantes), 124/124 tests
verts, build APK debug validé.

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

test/presentation/home_screen_test.dart

@@ -146,6 +146,17 @@ final class _FakeBootstrap implements AppDependencies {
         clock: _FakeClock(DateTime.utc(2026, 7, 17, 12)),
         deviceId: 'device-1',
       ),
+      shareUseCases = ShareUseCases(
+        tokenStore: _FakeAuthTokenStore(),
+        remoteShareApi: _FakeRemoteShareApi(),
+        inboxRepository: _FakeShareInboxRepository(),
+        pendingActionRepository: _FakePendingShareActionRepository(),
+        localChanges: _FakeLocalSyncChangeRepository(),
+        programRepository: _FakeProgramRepository(),
+        templateRepository: _FakeWorkoutTemplateRepository(),
+        clock: _FakeClock(DateTime.utc(2026, 7, 17, 12)),
+        ids: _FakeIds(),
+      ),
       activeWorkoutSessionUseCases = ActiveWorkoutSessionUseCases(
         sessionRepository: activeRepository,
         templateRepository: _FakeWorkoutTemplateRepository(),
@@ -207,6 +218,9 @@ final class _FakeBootstrap implements AppDependencies {
   @override
   final SyncUseCases syncUseCases;
 
+  @override
+  final ShareUseCases shareUseCases;
+
   @override
   final ExerciseUseCases exerciseUseCases;
 
@@ -390,6 +404,72 @@ final class _FakeLocalSyncChangeRepository
   ) async {}
 }
 
+final class _FakeRemoteShareApi implements RemoteShareApi {
+  @override
+  Future<RemoteSyncedItem> acceptShare(String shareId, String token) async {
+    throw const RemoteAuthException(RemoteAuthFailure.network);
+  }
+
+  @override
+  Future<void> declineShare(String shareId, String token) async {}
+
+  @override
+  Future<List<ShareInboxItem>> fetchInbox(String token) async => const [];
+
+  @override
+  Future<void> revokeShare(String shareId, String token) async {}
+
+  @override
+  Future<RemoteShareSendResult> sendShare({
+    required ShareResourceType resourceType,
+    required Map<String, Object?> payload,
+    required List<String> recipientEmails,
+    required String token,
+  }) async {
+    return const RemoteShareSendResult(
+      shareId: 'share-1',
+      recipientUserIds: [],
+      unresolvedEmails: [],
+    );
+  }
+}
+
+final class _FakeShareInboxRepository implements ShareInboxRepository {
+  @override
+  Future<ShareInboxItem?> findByShareId(String shareId) async => null;
+
+  @override
+  Future<List<ShareInboxItem>> listAll() async => const [];
+
+  @override
+  Future<void> markStatus(
+    String shareId,
+    ShareInboxStatus status,
+    DateTime respondedAt,
+  ) async {}
+
+  @override
+  Future<void> upsert(ShareInboxItem item) async {}
+
+  @override
+  Future<void> upsertAll(List<ShareInboxItem> items) async {}
+}
+
+final class _FakePendingShareActionRepository
+    implements PendingShareActionRepository {
+  @override
+  Future<void> add(PendingShareAction action) async {}
+
+  @override
+  Future<List<PendingShareAction>> listPending() async => const [];
+
+  @override
+  Future<void> markFailed(String id, DateTime attemptedAt) async {}
+
+  @override
+  Future<void> markSucceeded(String id, DateTime attemptedAt) async {}
+}
+
 final class _FakeActiveSessionRepository implements ActiveSessionRepository {
   ActiveWorkoutSession? session;
   final restStates = <ActiveRestState>[];