feat: add remote pull and push

test/bar_screen_view_model_test.dart

@@ -3,27 +3,36 @@ import 'package:kooltab2/models/product.dart';
 import 'package:kooltab2/models/tab_item.dart';
 import 'package:kooltab2/services/bar_tab_service.dart';
 import 'package:kooltab2/services/product_service.dart';
+import 'package:kooltab2/services/remote_sync_service.dart';
 import 'package:kooltab2/viewmodels/bar_screen_view_model.dart';
 import 'package:kooltab2/viewmodels/inventory_view_model.dart';
+import 'package:kooltab2/viewmodels/remote_sync_view_model.dart';
 import 'package:mocktail/mocktail.dart';
 
 class MockBarTabService extends Mock implements BarTabService {}
 
 class MockProductService extends Mock implements ProductService {}
 
+class MockRemoteSyncService extends Mock implements RemoteSyncService {}
+
 void main() {
   late MockBarTabService barTabService;
   late MockProductService productService;
   late InventoryViewModel inventory;
   late BarScreenViewModel viewModel;
+  late RemoteSyncViewModel remoteSyncViewModel;
 
   setUp(() {
     barTabService = MockBarTabService();
     productService = MockProductService();
     inventory = InventoryViewModel(productService: productService);
+    remoteSyncViewModel = RemoteSyncViewModel(
+      syncService: MockRemoteSyncService(),
+    );
     viewModel = BarScreenViewModel(
       barTabService: barTabService,
       inventory: inventory,
+      remoteSyncViewModel: remoteSyncViewModel,
     );
   });
 

test/edit_tab_dialog_test.dart

@@ -4,8 +4,10 @@ import 'package:kooltab2/l10n/app_localizations.dart';
 import 'package:kooltab2/models/bar_tab.dart';
 import 'package:kooltab2/services/bar_tab_service.dart';
 import 'package:kooltab2/services/product_service.dart';
+import 'package:kooltab2/services/remote_sync_service.dart';
 import 'package:kooltab2/viewmodels/bar_screen_view_model.dart';
 import 'package:kooltab2/viewmodels/inventory_view_model.dart';
+import 'package:kooltab2/viewmodels/remote_sync_view_model.dart';
 import 'package:kooltab2/views/dialogs/edit_tab_dialog.dart';
 import 'package:mocktail/mocktail.dart';
 import 'package:provider/provider.dart';
@@ -14,15 +16,21 @@ class MockBarTabService extends Mock implements BarTabService {}
 
 class MockProductService extends Mock implements ProductService {}
 
+class MockRemoteSyncService extends Mock implements RemoteSyncService {}
+
 void main() {
   testWidgets('edit dialog disposes its controller after closing', (
     tester,
   ) async {
     final barTabService = MockBarTabService();
     final productService = MockProductService();
+    final remoteSyncViewModel = RemoteSyncViewModel(
+      syncService: MockRemoteSyncService(),
+    );
     final viewModel = BarScreenViewModel(
       barTabService: barTabService,
       inventory: InventoryViewModel(productService: productService),
+      remoteSyncViewModel: remoteSyncViewModel,
     );
     final tab = BarTab(
       id: 'tab-1',