修复工作人员端令牌失效后的登录恢复

apps/service_app/lib/app/router.dart

@@ -1,3 +1,5 @@
+// 功能描述：配置工作人员端路由、鉴权守卫及登录后安全回跳。
+// 版本：1.1.0
 import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 
@@ -7,21 +9,35 @@ import '../ui/features/preflight/preflight_page.dart';
 import '../ui/features/profile/profile_page.dart';
 import '../ui/features/work/work_detail_page.dart';
 import '../ui/features/work/work_list_page.dart';
+import 'auth_navigation.dart';
 import 'dependencies.dart';
 
-GoRouter createRouter(AppDependencies dependencies) => GoRouter(
-  initialLocation: '/preflight',
+GoRouter createRouter(
+  AppDependencies dependencies, {
+  String initialLocation = '/preflight',
+}) => GoRouter(
+  initialLocation: initialLocation,
   refreshListenable: dependencies.session,
   redirect: (context, state) {
     final login = state.matchedLocation == '/login';
-    if (!dependencies.session.isAuthenticated && !login) return '/login';
-    if (dependencies.session.isAuthenticated && login) return '/preflight';
+    if (!dependencies.session.isAuthenticated && !login) {
+      return buildAuthLocation(
+        redirectTarget: state.uri.toString(),
+        sessionExpired: dependencies.session.hasExpired,
+      );
+    }
+    if (dependencies.session.isAuthenticated && login) {
+      return sanitizeRedirectTarget(state.uri.queryParameters['redirect']) ?? '/preflight';
+    }
     return null;
   },
   routes: [
     GoRoute(
       path: '/login',
-      builder: (context, state) => LoginPage(session: dependencies.session),
+      builder: (context, state) => LoginPage(
+        session: dependencies.session,
+        showSessionExpiredMessage: state.uri.queryParameters['reason'] == 'expired',
+      ),
     ),
     GoRoute(
       path: '/preflight',