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

backend/src/v1/agent/router.py

@@ -68,12 +68,12 @@ def _verified_access_token_for_user(
     *,
     authorization: str | None,
     current_user: CurrentUser,
-) -> str | None:
+) -> str:
     if not isinstance(authorization, str):
-        return None
+        raise HTTPException(status_code=401, detail="Unauthorized")
     normalized = authorization.strip()
     if not normalized:
-        return None
+        raise HTTPException(status_code=401, detail="Unauthorized")
     if not normalized.lower().startswith("bearer "):
         raise HTTPException(status_code=401, detail="Unauthorized")
     token = normalized[7:].strip()