独立的开发者账户体系：模型广场、按张/按秒计费、Key 管理、调用文档。返回上游资产链接，平台不落库转存。
curl -X POST "https://openapi.sczhiyun.net/v1/images/generations" \
-H "Authorization: Bearer sk-xxxxxxxx" \
-H "Content-Type: application/json" \
-H "X-Idempotency-Key: 3f1c9e2a-8b7d-4f1a-9c5e" \
-d '{
"model": "1",
"prompt": "赛博朋克风格的夜市街头",
"ratio": "1:1",
"quality": "1K"
}'