feat(flutter): 统一空列表占位组件

test/library/favorites_page_test.dart

@@ -10,6 +10,7 @@ import 'package:fruitshorts/core/data/services/auth_controller.dart';
 import 'package:fruitshorts/core/data/services/auth_session_store.dart';
 import 'package:fruitshorts/core/data/services/favorite_controller.dart';
 import 'package:fruitshorts/core/platform/haptics.dart';
+import 'package:fruitshorts/core/widgets/empty_state.dart';
 import 'package:fruitshorts/l10n/app_localizations.dart';
 import 'package:fruitshorts/pages/favorites/favorites_page.dart';
 import 'package:provider/provider.dart';
@@ -83,6 +84,7 @@ void main() {
     await _pumpPage(tester, auth: auth, favorites: favorites);
 
     expect(find.byKey(const Key('favorites-empty')), findsOneWidget);
+    expect(find.byType(EmptyState), findsOneWidget);
   });
 
   testWidgets('should_show_retry_when_favorite_list_fails', (tester) async {