refactor(auth): 重构认证模块架构 - 将Gateway层组件从Business层分离

范围：src/gateway/auth/, src/business/auth/, src/app.module.ts
涉及文件：
- 新增：src/gateway/auth/ 目录及所有文件
- 移动：Controller、Guard、Decorator、DTO从business层移至gateway层
- 修改：src/business/auth/index.ts（移除Gateway层组件导出）
- 修改：src/app.module.ts（使用AuthGatewayModule替代AuthModule）

主要改进：
- 明确Gateway层和Business层的职责边界
- Controller、Guard、Decorator属于Gateway层职责
- Business层专注于业务逻辑和服务
- 符合分层架构设计原则

src/gateway/auth/register.controller.spec.ts

@@ -0,0 +1,231 @@
+/**
+ * RegisterController 单元测试
+ * 
+ * 功能描述：
+ * - 测试注册控制器的HTTP请求处理
+ * - 验证API响应格式和状态码
+ * - 测试邮箱验证流程
+ * 
+ * 最近修改：
+ * - 2026-01-14: 架构重构 - 从business层移动到gateway层 (修改者: moyin)
+ * - 2026-01-12: 代码规范优化 - 创建缺失的控制器测试文件 (修改者: moyin)
+ * 
+ * @author moyin
+ * @version 1.1.0
+ * @since 2026-01-12
+ * @lastModified 2026-01-14
+ */
+
+import { Test, TestingModule } from '@nestjs/testing';
+import { Response } from 'express';
+import { HttpStatus } from '@nestjs/common';
+import { RegisterController } from './register.controller';
+import { RegisterService } from '../../business/auth/register.service';
+
+describe('RegisterController', () => {
+  let controller: RegisterController;
+  let registerService: jest.Mocked<RegisterService>;
+  let mockResponse: jest.Mocked<Response>;
+
+  beforeEach(async () => {
+    const mockRegisterService = {
+      register: jest.fn(),
+      sendEmailVerification: jest.fn(),
+      verifyEmailCode: jest.fn(),
+      resendEmailVerification: jest.fn(),
+    };
+
+    const module: TestingModule = await Test.createTestingModule({
+      controllers: [RegisterController],
+      providers: [
+        {
+          provide: RegisterService,
+          useValue: mockRegisterService,
+        },
+      ],
+    }).compile();
+
+    controller = module.get<RegisterController>(RegisterController);
+    registerService = module.get(RegisterService);
+
+    // Mock Response object
+    mockResponse = {
+      status: jest.fn().mockReturnThis(),
+      json: jest.fn().mockReturnThis(),
+    } as any;
+  });
+
+  it('should be defined', () => {
+    expect(controller).toBeDefined();
+  });
+
+  describe('register', () => {
+    it('should handle successful registration', async () => {
+      const registerDto = {
+        username: 'newuser',
+        password: 'password123',
+        nickname: '新用户',
+        email: 'newuser@example.com',
+        email_verification_code: '123456'
+      };
+
+      const mockResult = {
+        success: true,
+        data: {
+          user: { 
+            id: '1', 
+            username: 'newuser',
+            nickname: '新用户',
+            role: 1,
+            created_at: new Date()
+          },
+          access_token: 'token',
+          refresh_token: 'refresh_token',
+          expires_in: 3600,
+          token_type: 'Bearer',
+          is_new_user: true,
+          message: '注册成功'
+        },
+        message: '注册成功'
+      };
+
+      registerService.register.mockResolvedValue(mockResult);
+
+      await controller.register(registerDto, mockResponse);
+
+      expect(registerService.register).toHaveBeenCalledWith(registerDto);
+      expect(mockResponse.status).toHaveBeenCalledWith(HttpStatus.CREATED);
+      expect(mockResponse.json).toHaveBeenCalledWith(mockResult);
+    });
+
+    it('should handle registration failure', async () => {
+      const registerDto = {
+        username: 'existinguser',
+        password: 'password123',
+        nickname: '用户'
+      };
+
+      const mockResult = {
+        success: false,
+        message: '用户名已存在',
+        error_code: 'REGISTER_FAILED'
+      };
+
+      registerService.register.mockResolvedValue(mockResult);
+
+      await controller.register(registerDto, mockResponse);
+
+      expect(mockResponse.status).toHaveBeenCalledWith(HttpStatus.BAD_REQUEST);
+      expect(mockResponse.json).toHaveBeenCalledWith(mockResult);
+    });
+  });
+
+  describe('sendEmailVerification', () => {
+    it('should handle email verification in production mode', async () => {
+      const sendEmailDto = {
+        email: 'test@example.com'
+      };
+
+      const mockResult = {
+        success: true,
+        data: { is_test_mode: false },
+        message: '验证码已发送，请查收邮件'
+      };
+
+      registerService.sendEmailVerification.mockResolvedValue(mockResult);
+
+      await controller.sendEmailVerification(sendEmailDto, mockResponse);
+
+      expect(registerService.sendEmailVerification).toHaveBeenCalledWith('test@example.com');
+      expect(mockResponse.status).toHaveBeenCalledWith(HttpStatus.OK);
+      expect(mockResponse.json).toHaveBeenCalledWith(mockResult);
+    });
+
+    it('should handle email verification in test mode', async () => {
+      const sendEmailDto = {
+        email: 'test@example.com'
+      };
+
+      const mockResult = {
+        success: false,
+        data: { 
+          verification_code: '123456',
+          is_test_mode: true 
+        },
+        message: '⚠️ 测试模式：验证码已生成但未真实发送。请在控制台查看验证码，或配置邮件服务以启用真实发送。',
+        error_code: 'TEST_MODE_ONLY'
+      };
+
+      registerService.sendEmailVerification.mockResolvedValue(mockResult);
+
+      await controller.sendEmailVerification(sendEmailDto, mockResponse);
+
+      expect(mockResponse.status).toHaveBeenCalledWith(HttpStatus.PARTIAL_CONTENT);
+      expect(mockResponse.json).toHaveBeenCalledWith(mockResult);
+    });
+  });
+
+  describe('verifyEmail', () => {
+    it('should handle email verification successfully', async () => {
+      const verifyEmailDto = {
+        email: 'test@example.com',
+        verification_code: '123456'
+      };
+
+      const mockResult = {
+        success: true,
+        message: '邮箱验证成功'
+      };
+
+      registerService.verifyEmailCode.mockResolvedValue(mockResult);
+
+      await controller.verifyEmail(verifyEmailDto, mockResponse);
+
+      expect(registerService.verifyEmailCode).toHaveBeenCalledWith('test@example.com', '123456');
+      expect(mockResponse.status).toHaveBeenCalledWith(HttpStatus.OK);
+      expect(mockResponse.json).toHaveBeenCalledWith(mockResult);
+    });
+
+    it('should handle invalid verification code', async () => {
+      const verifyEmailDto = {
+        email: 'test@example.com',
+        verification_code: '000000'
+      };
+
+      const mockResult = {
+        success: false,
+        message: '验证码错误',
+        error_code: 'INVALID_VERIFICATION_CODE'
+      };
+
+      registerService.verifyEmailCode.mockResolvedValue(mockResult);
+
+      await controller.verifyEmail(verifyEmailDto, mockResponse);
+
+      expect(mockResponse.status).toHaveBeenCalledWith(HttpStatus.BAD_REQUEST);
+      expect(mockResponse.json).toHaveBeenCalledWith(mockResult);
+    });
+  });
+
+  describe('resendEmailVerification', () => {
+    it('should handle resend email verification successfully', async () => {
+      const sendEmailDto = {
+        email: 'test@example.com'
+      };
+
+      const mockResult = {
+        success: true,
+        data: { is_test_mode: false },
+        message: '验证码已重新发送，请查收邮件'
+      };
+
+      registerService.resendEmailVerification.mockResolvedValue(mockResult);
+
+      await controller.resendEmailVerification(sendEmailDto, mockResponse);
+
+      expect(registerService.resendEmailVerification).toHaveBeenCalledWith('test@example.com');
+      expect(mockResponse.status).toHaveBeenCalledWith(HttpStatus.OK);
+      expect(mockResponse.json).toHaveBeenCalledWith(mockResult);
+    });
+  });
+});