feat(client): 全模块 API 对接 + 修复登陆跳转 + 菜单 UI 优化

API 对接：
- 入库/出库/库存/财务/往来单位/基础数据全部对接后端 REST API
- 新增 repositories、providers、models 层，统一分层架构
- auth 从 flutter_secure_storage 迁移到 shared_preferences

登陆跳转修复：
- 将 _RouterNotifier 提取为独立 Riverpod provider，appRouterProvider
  使用 ref.read 避免依赖链导致 router 重建后跳回 /login
- redirect 函数新增 initialized 守卫，防止 auth 未恢复时误重定向
- 添加调试日志（Router/Auth/ApiClient）定位 401 触发的 logout 链路

退出菜单 UI：
- 去掉 ListTile，改用 Row + 自定义 padding，文字左对齐
- MouseRegion + AnimatedContainer 实现 hover 高亮（普通项蓝底/退出红底）
- 菜单圆角 6px，elevation 8，分割线高度 1px

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/lib/repositories/auth_repository.dart

@@ -11,16 +11,16 @@ class AuthException implements Exception {
 
 class AuthRepository {
   /// POST /api/v1/auth/login
-  /// Request:  { hotel_code, username, password }
+  /// Request:  { shop_code, username, password }
   /// Response: { data: { access_token, refresh_token, expires_in, user: { id, username, real_name, role } } }
   static Future<AuthUser> login({
-    required String hotelCode,
+    required String shopCode,
     required String username,
     required String password,
   }) async {
     try {
       final resp = await PublicApiClient.post('/auth/login', data: {
-        'hotel_code': hotelCode,
+        'shop_code': shopCode,
         'username': username,
         'password': password,
       });
@@ -33,8 +33,8 @@ class AuthRepository {
         refreshToken: data['refresh_token'] as String,
         username: user['username'] as String,
         realName: user['real_name'] as String? ?? username,
-        hotelNo: hotelCode,
-        hotelId: (user['id'] as num).toInt(),
+        shopNo: shopCode,
+        shopId: (data['shop_id'] as num).toInt(),
       );
     } on DioException catch (e) {
       final msg = e.response?.data?['error'] as String?;