{
    "service": "NexTech UGC 文件上传服务",
    "version": "2.0",
    "endpoints": {
        "POST \/upload": "上传文件（multipart\/form-data, field: file, max 5MB）",
        "GET \/files\/{filename}": "下载文件",
        "POST \/api\/cleanup (list)": "列出所有文件（需 secret 密钥）",
        "POST \/api\/cleanup (delete)": "删除所有文件（需 secret 密钥）"
    },
    "limits": {
        "max_file_size": "5MB",
        "retention": "文件持久保留，通过 \/api\/cleanup 手动清理"
    }
}