fix(登录): 在登录前重置登录上下文并改进鉴权错误处理

Author: lhgr

lib/api/auth/auth_api.dart

@@ -40,6 +40,15 @@ Y/akVmYNtghKZzz6jwIDAQAB
     await loginWithEncrypted(account: account, encryptedPassword: encryptedPwd);
   }
 
+  Future<void> resetLoginContext({String? account}) async {
+    if (account == null || account.trim().isEmpty) {
+      _timetableLoginStates.clear();
+    } else {
+      _timetableLoginStates.remove(account.trim());
+    }
+    await _client.cookieJar.deleteAll();
+  }
+
   Future<void> ensureTimetableLogin({
     required String account,
     String? password,

lib/api/course/course_api.dart

@@ -77,6 +77,9 @@ class CourseApi {
           allowReloginRetry: false,
         );
       }
+      if (_looksLikeAuthError(parsed)) {
+        throw Exception(_authErrorMessage(parsed));
+      }
       return parsed;
     } catch (e) {
       if (!allowReloginRetry) rethrow;
@@ -116,4 +119,10 @@ class CourseApi {
     if (data.containsKey('code') || data.containsKey('msg')) return true;
     return false;
   }
+
+  String _authErrorMessage(Map<String, dynamic> data) {
+    final msg = (data['msg'] ?? '').toString().trim();
+    if (msg.isNotEmpty) return msg;
+    return '课表鉴权失败，请重新登录';
+  }
 }

lib/pages/ClassSchedule/controllers/schedule_controller.dart

@@ -274,6 +274,11 @@ class ScheduleController {
       persistLastViewed: persistLastViewed,
       updateWidgetPins: shouldPinWidget,
     );
+    final loadedWeek = (data.weekNum ?? '').trim();
+    final loadedWeeks = data.weekList;
+    if (loadedWeek.isEmpty || loadedWeeks == null || loadedWeeks.isEmpty) {
+      throw Exception("课表鉴权失败，请重新登录");
+    }
 
     if (weekNum == null && yearTerm == null) {
       final now = DateTime.now();

lib/pages/Login/Login.dart

@@ -195,6 +195,7 @@ class _LoginPageState extends State<LoginPage> {
     setState(() => _isLoading = true);
 
     try {
+      await _authApi.resetLoginContext();
       if (useSavedPassword) {
         await _authApi.loginWithEncrypted(
           account: account,

lib/pages/Mine/mine_logout_dialog.dart

@@ -1,3 +1,4 @@
+import 'package:cqut/api/auth/auth_api.dart';
 import 'package:flutter/material.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
@@ -17,6 +18,7 @@ Future<void> showMineLogoutDialog(BuildContext context) async {
             final prefs = await SharedPreferences.getInstance();
             await prefs.remove('account');
             await prefs.remove('encrypted_password');
+            await AuthApi().resetLoginContext();
             if (context.mounted) {
               Navigator.pop(context);
               ScaffoldMessenger.of(