chore: 清理旧文件和更新项目配置

- 删除旧的DTO文件（已迁移到对应业务模块）
- 删除旧的测试目录结构
- 删除过时的API目录
- 更新package.json配置
- 移除不再使用的文件

package.json

@@ -29,6 +29,7 @@
     "@nestjs/platform-socket.io": "^10.4.20",
     "@nestjs/schedule": "^4.1.2",
     "@nestjs/swagger": "^11.2.3",
+    "@nestjs/throttler": "^6.5.0",
     "@nestjs/typeorm": "^11.0.0",
     "@nestjs/websockets": "^10.4.20",
     "@types/archiver": "^7.0.0",