feat: 添加设置页、关于页与账号注销功能，开启网络日志

1.  新增账号注销API接口与设置页菜单，实现完整注销流程
2.  新增关于APP页面，展示隐私政策、用户协议与版本信息
3.  在我的页面添加设置入口，跳转设置页
4.  优化头像上传逻辑，移除预览弹窗步骤并简化流程
5.  开启网络日志打印，方便调试网络请求

lib/core/router/app_router.dart

@@ -13,6 +13,8 @@ import 'package:new_learn/features/class/my_update_detail_page.dart';
 import 'package:new_learn/core/api/class/model.dart';
 import 'package:new_learn/features/my/my_page.dart';
 import 'package:new_learn/features/my/my_point/my_point_page.dart';
+import 'package:new_learn/features/my/settings/settings_page.dart';
+import 'package:new_learn/features/my/settings/about_app_page.dart';
 import 'package:new_learn/features/recite/recite_page.dart';
 import 'package:new_learn/features/task/task_page.dart';
 import 'package:new_learn/core/router/main_tab_page.dart';
@@ -122,6 +124,8 @@ final GoRouter appRouter = GoRouter(
           MyUpdateDetailPage(initialPost: state.extra as UserPostDto),
     ),
     GoRoute(path: '/myPoint', builder: (_, _) => const MyPointPage()),
+    GoRoute(path: '/settings', builder: (_, _) => const SettingsPage()),
+    GoRoute(path: '/about-app', builder: (_, _) => const AboutAppPage()),
     // ---------- 首次启动隐私协议页 ----------
     GoRoute(
       path: '/privacy-consent',