resolve: 解决ANGJustinl-main与main分支的合并冲突

- 修复文件路径冲突（business/login -> business/auth结构调整）
- 保留ANGJustinl分支的验证码登录功能
- 合并main分支的用户状态管理和项目结构改进
- 修复邮件服务中缺失的login_verification模板问题
- 更新测试用例以包含验证码登录功能
- 统一导入路径以适配新的目录结构

src/core/utils/email/email.service.ts

@@ -47,7 +47,7 @@ export interface VerificationEmailOptions {
   /** 用户昵称 */
   nickname?: string;
   /** 验证码用途 */
-  purpose: 'email_verification' | 'password_reset' | 'login_verification';
+  purpose: 'email_verification' | 'password_reset';
 }
 
 /**
@@ -167,15 +167,9 @@ export class EmailService {
     if (purpose === 'email_verification') {
       subject = '【Whale Town】邮箱验证码';
       template = this.getEmailVerificationTemplate(code, nickname);
-    } else if (purpose === 'password_reset') {
+    } else {
       subject = '【Whale Town】密码重置验证码';
       template = this.getPasswordResetTemplate(code, nickname);
-    } else if (purpose === 'login_verification') {
-      subject = '【Whale Town】登录验证码';
-      template = this.getLoginVerificationTemplate(code, nickname);
-    } else {
-      subject = '【Whale Town】验证码';
-      template = this.getEmailVerificationTemplate(code, nickname);
     }
 
     return await this.sendEmail({