refactor: 移除前端 Mock API，新增共享组件，优化认证流程

- 删除 mock_api_client、mock_calendar_service、mock_history_service
- 新增 fixed_length_code_input、link_button、message_composer 共享组件
- 优化登录/注册/密码重置页面使用新组件
- 简化 injection.dart 移除 mock 分支
- 更新 env.dart 配置（BACKEND_URL 替换 API_URL）
- 后端 agentscope 工具和测试更新
- 重构 AGENTS.md 文档结构
- 新增 deploy/ 目录和 protocol 文档

apps/lib/features/settings/ui/screens/change_password_screen.dart

@@ -5,6 +5,7 @@ import 'package:go_router/go_router.dart';
 import '../../../../core/theme/design_tokens.dart';
 import '../../../../core/di/injection.dart';
 import '../../../../shared/widgets/app_button.dart';
+import '../../../../shared/widgets/fixed_length_code_input.dart';
 import '../../../../shared/widgets/toast/toast.dart';
 import '../../../../shared/widgets/toast/toast_type.dart';
 import '../../../../shared/widgets/page_header.dart' as widgets;
@@ -170,7 +171,7 @@ class __ChangePasswordViewState extends State<_ChangePasswordView> {
         return Column(
           crossAxisAlignment: CrossAxisAlignment.start,
           children: [
-            _buildCodeInput(state.code.displayError != null, state),
+            _buildCodeInput(state),
             const SizedBox(height: 16),
             _buildPasswordInput(state.newPassword.displayError != null),
             const SizedBox(height: 16),
@@ -185,7 +186,7 @@ class __ChangePasswordViewState extends State<_ChangePasswordView> {
     );
   }
 
-  Widget _buildCodeInput(bool hasError, ResetPasswordState state) {
+  Widget _buildCodeInput(ResetPasswordState state) {
     return Column(
       crossAxisAlignment: CrossAxisAlignment.start,
       children: [
@@ -201,18 +202,26 @@ class __ChangePasswordViewState extends State<_ChangePasswordView> {
         Row(
           children: [
             Expanded(
-              child: TextField(
+              child: FixedLengthCodeInput(
                 controller: _codeController,
+                length: 6,
+                semanticLabel: '修改密码验证码输入框',
                 keyboardType: TextInputType.number,
+                allowedCharacters: const {
+                  '0',
+                  '1',
+                  '2',
+                  '3',
+                  '4',
+                  '5',
+                  '6',
+                  '7',
+                  '8',
+                  '9',
+                },
                 onChanged: (value) {
                   context.read<ResetPasswordCubit>().codeChanged(value);
                 },
-                decoration: InputDecoration(
-                  hintText: '请输入 6 位验证码',
-                  errorText: hasError ? ' ' : null,
-                  filled: true,
-                  fillColor: AppColors.white,
-                ),
               ),
             ),
             const SizedBox(width: 12),