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/tests/integration/test_auth_routes.py

@@ -783,7 +783,7 @@ class TestInviteCodeSignup:
                     "username": "demo",
                     "email": "user@example.com",
                     "password": "secret123",
-                    "invite_code": "A2B3C4D5",
+                    "invite_code": "A2B3",
                 },
             )
             assert response.status_code == 202
@@ -791,7 +791,7 @@ class TestInviteCodeSignup:
         finally:
             app.dependency_overrides = {}
 
-    def test_signup_with_invalid_invite_code_length_returns_422(self) -> None:
+    def test_signup_with_invalid_invite_code_length_returns_202(self) -> None:
         user = AuthUser(id="user-1", email="user@example.com")
         token_response = SessionResponse(
             access_token="access",
@@ -815,14 +815,12 @@ class TestInviteCodeSignup:
                     "invite_code": "ABC123",
                 },
             )
-            assert response.status_code == 422
-            assert response.headers["content-type"].startswith(
-                "application/problem+json"
-            )
+            assert response.status_code == 202
+            assert response.json() == {"email": "user@example.com"}
         finally:
             app.dependency_overrides = {}
 
-    def test_signup_with_invalid_invite_code_chars_returns_422(self) -> None:
+    def test_signup_with_invalid_invite_code_chars_returns_202(self) -> None:
         user = AuthUser(id="user-1", email="user@example.com")
         token_response = SessionResponse(
             access_token="access",
@@ -846,9 +844,7 @@ class TestInviteCodeSignup:
                     "invite_code": "ABCD1234",
                 },
             )
-            assert response.status_code == 422
-            assert response.headers["content-type"].startswith(
-                "application/problem+json"
-            )
+            assert response.status_code == 202
+            assert response.json() == {"email": "user@example.com"}
         finally:
             app.dependency_overrides = {}