[POST]
summary = "进程插件示例：获取预签名上传 URL（设备直传 Minio，不经网关）"
subject = "demo.storage.presign_upload"
params = ["filename: str"]
auth_required = false

[POST.response_model]
object_key = { type = "str", required = true }
presigned_url = { type = "str", required = true }
method = { type = "str", required = true }
expires = { type = "int", required = true }
timestamp = { type = "float", required = true }