refactor: 重构项目目录与代码结构，清理冗余文件

本次提交进行了大规模的项目结构调整：
1. 调整文件目录归属，将模块代码按功能域重新组织
2. 删除多处冗余的DTO、实体类和模块文件
3. 统一了常量、装饰器、工具类的存放位置
4. 修复了`.gitignore`的日志目录匹配规则
5. 新增了健康检查、认证、用户、剧集、订单等核心业务模块

guards/permissions.guard.ts

@@ -0,0 +1,54 @@
+import { CanActivate, ExecutionContext, ForbiddenException, Injectable } from '@nestjs/common';
+import { Reflector } from '@nestjs/core';
+import { Request } from 'express';
+import {
+  REQUIRED_PERMISSIONS_METADATA,
+} from '../decorators/require-permissions.decorator';
+import { AdminUserRecord } from '../interfaces/admin-records.interface';
+import { AdminService } from '../admin.service';
+
+@Injectable()
+export class PermissionsGuard implements CanActivate {
+  constructor(
+    private readonly reflector: Reflector,
+    private readonly adminService: AdminService,
+  ) {}
+
+  async canActivate(context: ExecutionContext): Promise<boolean> {
+    const required =
+      this.reflector.getAllAndOverride<string[]>(
+        REQUIRED_PERMISSIONS_METADATA,
+        [context.getHandler(), context.getClass()],
+      ) ?? [];
+
+    if (required.length === 0) {
+      return true;
+    }
+
+    const request = context
+      .switchToHttp()
+      .getRequest<Request & { adminUser?: AdminUserRecord }>();
+    const adminUser = request.adminUser;
+
+    if (!adminUser) {
+      throw new ForbiddenException('No permission');
+    }
+
+    if (adminUser.isSuperAdmin) {
+      return true;
+    }
+
+    const permissions = await this.adminService.getPermissionCodesForAdmin(
+      adminUser.id,
+    );
+    const allowed = required.every((permission) =>
+      permissions.includes(permission),
+    );
+
+    if (!allowed) {
+      throw new ForbiddenException('No permission');
+    }
+
+    return true;
+  }
+}