列出 Credential

curl --request GET \
  --url 'https://{workspace_id}.{region}.maas.aliyuncs.com/api/v1/agentstudio/credentials' \
  --header 'Authorization: Bearer <YOUR_API_KEY>'

{
  "data": [
    {
      "id": "cred_01JXH5K2",
      "vault_id": "vault_01JXH5K2",
      "name": "OpenAI Key",
      "key": "OPENAI_API_KEY",
      "created_at": "2026-07-20T10:00:00Z",
      "updated_at": "2026-07-20T10:00:00Z",
      "workspace_id": "ws_xxx",
      "request_id": "req_xxx"
    }
  ],
  "has_more": false,
  "request_id": "req_xxx"
}