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({

src/core/utils/logger/log_management.service.ts

@@ -61,6 +61,15 @@ export class LogManagementService {
     this.maxSize = this.configService.get('LOG_MAX_SIZE', '10m');
   }
 
+  /**
+   * 获取日志目录的绝对路径
+   *
+   * 说明：用于后台打包下载 logs/ 整目录。
+   */
+  getLogDirAbsolutePath(): string {
+    return path.resolve(this.logDir);
+  }
+
   /**
    * 定期清理过期日志文件
    * 
@@ -307,6 +316,67 @@ export class LogManagementService {
     }
   }
 
+  /**
+   * 获取运行日志尾部（用于后台查看）
+   *
+   * 说明：
+   * - 开发环境默认读取 dev.log
+   * - 生产环境默认读取 app.log（可选 access/error）
+   * - 通过读取文件尾部一定字节数实现“近似 tail”，避免大文件全量读取
+   */
+  async getRuntimeLogTail(options?: {
+    type?: 'app' | 'access' | 'error' | 'dev';
+    lines?: number;
+  }): Promise<{
+    file: string;
+    updated_at: string;
+    lines: string[];
+  }> {
+    const isProduction = this.configService.get('NODE_ENV') === 'production';
+    const requestedLines = Math.max(1, Math.min(Number(options?.lines ?? 200), 2000));
+    const requestedType = options?.type;
+
+    const allowedFiles = isProduction
+      ? {
+          app: 'app.log',
+          access: 'access.log',
+          error: 'error.log',
+        }
+      : {
+          dev: 'dev.log',
+        };
+
+    const defaultType = isProduction ? 'app' : 'dev';
+    const typeKey = (requestedType && requestedType in allowedFiles ? requestedType : defaultType) as keyof typeof allowedFiles;
+    const fileName = allowedFiles[typeKey];
+    const filePath = path.join(this.logDir, fileName);
+
+    if (!fs.existsSync(filePath)) {
+      return { file: fileName, updated_at: new Date().toISOString(), lines: [] };
+    }
+
+    const stats = fs.statSync(filePath);
+    const maxBytes = 256 * 1024; // 256KB 足够覆盖常见的数百行日志
+    const readBytes = Math.min(stats.size, maxBytes);
+    const startPos = Math.max(0, stats.size - readBytes);
+
+    const fd = fs.openSync(filePath, 'r');
+    try {
+      const buffer = Buffer.alloc(readBytes);
+      fs.readSync(fd, buffer, 0, readBytes, startPos);
+      const text = buffer.toString('utf8');
+      const allLines = text.split(/\r?\n/).filter((l) => l.length > 0);
+      const tailLines = allLines.slice(-requestedLines);
+      return {
+        file: fileName,
+        updated_at: stats.mtime.toISOString(),
+        lines: tailLines,
+      };
+    } finally {
+      fs.closeSync(fd);
+    }
+  }
+
   /**
    * 解析最大文件数配置
    *