综合性能接近 K3，思考（thinking）效率更高；支持 thinking effort 档位调节（与 K3 的思考等级一致）；支持 1M 超长上下文
curl https://api.yourplatform.com/v1/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_API_KEY" \
-d '{
"model": "undefined",
"messages": [
{"role": "user", "content": "Hello!"}
],
"stream": true
}'