style(auth)：优化auth模块代码规范和测试覆盖

范围：src/business/auth/
- 统一命名规范和注释格式
- 完善文件头部注释和修改记录
- 分离登录和注册业务逻辑到独立服务
- 添加缺失的测试文件（JWT守卫、控制器测试）
- 清理未使用的测试文件
- 优化代码结构和依赖关系

src/business/auth/login.controller.ts

@@ -34,15 +34,12 @@ import { Controller, Post, Put, Body, HttpCode, HttpStatus, ValidationPipe, UseP
 import { ApiTags, ApiOperation, ApiResponse as SwaggerApiResponse, ApiBody } from '@nestjs/swagger';
 import { Response } from 'express';
 import { LoginService, ApiResponse, LoginResponse } from './login.service';
-import { LoginDto, RegisterDto, GitHubOAuthDto, ForgotPasswordDto, ResetPasswordDto, ChangePasswordDto, EmailVerificationDto, SendEmailVerificationDto, VerificationCodeLoginDto, SendLoginVerificationCodeDto, RefreshTokenDto } from './login.dto';
+import { LoginDto, GitHubOAuthDto, ForgotPasswordDto, ResetPasswordDto, ChangePasswordDto, VerificationCodeLoginDto, SendLoginVerificationCodeDto, RefreshTokenDto, SendEmailVerificationDto } from './login.dto';
 import { 
   LoginResponseDto, 
-  RegisterResponseDto, 
   GitHubOAuthResponseDto, 
   ForgotPasswordResponseDto, 
   CommonResponseDto,
-  TestModeEmailVerificationResponseDto,
-  SuccessEmailVerificationResponseDto,
   RefreshTokenResponseDto
 } from './login_response.dto';
 import { Throttle, ThrottlePresets } from '../../core/security_core/throttle.decorator';
@@ -51,14 +48,12 @@ import { Timeout, TimeoutPresets } from '../../core/security_core/timeout.decora
 // 错误代码到HTTP状态码的映射
 const ERROR_STATUS_MAP = {
   LOGIN_FAILED: HttpStatus.UNAUTHORIZED,
-  REGISTER_FAILED: HttpStatus.BAD_REQUEST,
   TEST_MODE_ONLY: HttpStatus.PARTIAL_CONTENT,
   TOKEN_REFRESH_FAILED: HttpStatus.UNAUTHORIZED,
   GITHUB_OAUTH_FAILED: HttpStatus.UNAUTHORIZED,
   SEND_CODE_FAILED: HttpStatus.BAD_REQUEST,
   RESET_PASSWORD_FAILED: HttpStatus.BAD_REQUEST,
   CHANGE_PASSWORD_FAILED: HttpStatus.BAD_REQUEST,
-  EMAIL_VERIFICATION_FAILED: HttpStatus.BAD_REQUEST,
   VERIFICATION_CODE_LOGIN_FAILED: HttpStatus.UNAUTHORIZED,
   INVALID_VERIFICATION_CODE: HttpStatus.BAD_REQUEST,
 } as const;
@@ -169,51 +164,6 @@ export class LoginController {
     this.handleResponse(result, res);
   }
 
-  /**
-   * 用户注册
-   * 
-   * @param registerDto 注册数据
-   * @returns 注册结果
-   */
-  @ApiOperation({ 
-    summary: '用户注册', 
-    description: '创建新用户账户。如果提供邮箱，需要先调用发送验证码接口获取验证码，然后在注册时提供验证码进行验证。' 
-  })
-  @ApiBody({ type: RegisterDto })
-  @SwaggerApiResponse({ 
-    status: 201, 
-    description: '注册成功', 
-    type: RegisterResponseDto 
-  })
-  @SwaggerApiResponse({ 
-    status: 400, 
-    description: '请求参数错误' 
-  })
-  @SwaggerApiResponse({ 
-    status: 409, 
-    description: '用户名或邮箱已存在' 
-  })
-  @SwaggerApiResponse({ 
-    status: 429, 
-    description: '注册请求过于频繁' 
-  })
-  @Throttle(ThrottlePresets.REGISTER)
-  @Timeout(TimeoutPresets.NORMAL)
-  @Post('register')
-  @UsePipes(new ValidationPipe({ transform: true }))
-  async register(@Body() registerDto: RegisterDto, @Res() res: Response): Promise<void> {
-    const result = await this.loginService.register({
-      username: registerDto.username,
-      password: registerDto.password,
-      nickname: registerDto.nickname,
-      email: registerDto.email,
-      phone: registerDto.phone,
-      email_verification_code: registerDto.email_verification_code
-    });
-
-    this.handleResponse(result, res, HttpStatus.CREATED);
-  }
-
   /**
    * GitHub OAuth登录
    * 
@@ -378,120 +328,6 @@ export class LoginController {
     this.handleResponse(result, res);
   }
 
-  /**
-   * 发送邮箱验证码
-   * 
-   * @param sendEmailVerificationDto 发送验证码数据
-   * @param res Express响应对象
-   * @returns 发送结果
-   */
-  @ApiOperation({ 
-    summary: '发送邮箱验证码', 
-    description: '向指定邮箱发送验证码' 
-  })
-  @ApiBody({ type: SendEmailVerificationDto })
-  @SwaggerApiResponse({ 
-    status: 200, 
-    description: '验证码发送成功（真实发送模式）', 
-    type: SuccessEmailVerificationResponseDto 
-  })
-  @SwaggerApiResponse({ 
-    status: 206, 
-    description: '测试模式：验证码已生成但未真实发送', 
-    type: TestModeEmailVerificationResponseDto 
-  })
-  @SwaggerApiResponse({ 
-    status: 400, 
-    description: '请求参数错误' 
-  })
-  @SwaggerApiResponse({ 
-    status: 429, 
-    description: '发送频率过高' 
-  })
-  @Throttle(ThrottlePresets.SEND_CODE_PER_EMAIL)
-  @Timeout(TimeoutPresets.EMAIL_SEND)
-  @Post('send-email-verification')
-  @UsePipes(new ValidationPipe({ transform: true }))
-  async sendEmailVerification(
-    @Body() sendEmailVerificationDto: SendEmailVerificationDto,
-    @Res() res: Response
-  ): Promise<void> {
-    const result = await this.loginService.sendEmailVerification(sendEmailVerificationDto.email);
-    this.handleResponse(result, res);
-  }
-
-  /**
-   * 验证邮箱验证码
-   * 
-   * @param emailVerificationDto 邮箱验证数据
-   * @returns 验证结果
-   */
-  @ApiOperation({ 
-    summary: '验证邮箱验证码', 
-    description: '使用验证码验证邮箱' 
-  })
-  @ApiBody({ type: EmailVerificationDto })
-  @SwaggerApiResponse({ 
-    status: 200, 
-    description: '邮箱验证成功', 
-    type: CommonResponseDto 
-  })
-  @SwaggerApiResponse({ 
-    status: 400, 
-    description: '验证码错误或已过期' 
-  })
-  @Post('verify-email')
-  @UsePipes(new ValidationPipe({ transform: true }))
-  async verifyEmail(@Body() emailVerificationDto: EmailVerificationDto, @Res() res: Response): Promise<void> {
-    const result = await this.loginService.verifyEmailCode(
-      emailVerificationDto.email,
-      emailVerificationDto.verification_code
-    );
-
-    this.handleResponse(result, res);
-  }
-
-  /**
-   * 重新发送邮箱验证码
-   * 
-   * @param sendEmailVerificationDto 发送验证码数据
-   * @param res Express响应对象
-   * @returns 发送结果
-   */
-  @ApiOperation({ 
-    summary: '重新发送邮箱验证码', 
-    description: '重新向指定邮箱发送验证码' 
-  })
-  @ApiBody({ type: SendEmailVerificationDto })
-  @SwaggerApiResponse({ 
-    status: 200, 
-    description: '验证码重新发送成功', 
-    type: ForgotPasswordResponseDto 
-  })
-  @SwaggerApiResponse({ 
-    status: 206, 
-    description: '测试模式：验证码已生成但未真实发送', 
-    type: ForgotPasswordResponseDto 
-  })
-  @SwaggerApiResponse({ 
-    status: 400, 
-    description: '邮箱已验证或用户不存在' 
-  })
-  @SwaggerApiResponse({ 
-    status: 429, 
-    description: '发送频率过高' 
-  })
-  @Throttle(ThrottlePresets.SEND_CODE)
-  @Post('resend-email-verification')
-  @UsePipes(new ValidationPipe({ transform: true }))
-  async resendEmailVerification(
-    @Body() sendEmailVerificationDto: SendEmailVerificationDto,
-    @Res() res: Response
-  ): Promise<void> {
-    const result = await this.loginService.resendEmailVerification(sendEmailVerificationDto.email);
-    this.handleResponse(result, res);
-  }
-
   /**
    * 验证码登录
    *