feat: add Flutter mobile clients and staff delivery API

apps/user_app/lib/app/app.dart

@@ -0,0 +1,26 @@
+import 'package:flutter/material.dart';
+
+import '../ui/core/app_theme.dart';
+import 'dependencies.dart';
+import 'router.dart';
+
+class UserClientApp extends StatefulWidget {
+  const UserClientApp({required this.dependencies, super.key});
+
+  final AppDependencies dependencies;
+
+  @override
+  State<UserClientApp> createState() => _UserClientAppState();
+}
+
+class _UserClientAppState extends State<UserClientApp> {
+  late final _router = createRouter(widget.dependencies);
+
+  @override
+  Widget build(BuildContext context) => MaterialApp.router(
+    title: '瓶安芯',
+    debugShowCheckedModeBanner: false,
+    theme: AppTheme.light(),
+    routerConfig: _router,
+  );
+}