[Feature] need a identify user agent for k8s client

**Feature Category**
- [x] Sandbox
- [ ] Actions
- [ ] Deployments
- [ ] SDK & API
- [ ] Envhub
- [ ] CLI
- [ ] Performance & Optimization
- [ ] Documentation & Examples

**Problem Statement**
现在k8s client默认的user agent是OpenAPI-Generator/35.0.0/python。不利于在审计日志中辨别请求来源。
**Proposed Solution**
设置一个代表rock身份的user agent
**Detailed Feature Description**

Start by locating the Python Kubernetes client setup and how its default OpenAPI-Generator/35.0.0/python user agent is configured. Confirm the chosen ROCK identifier appears in request metadata used by audit logs; the work is done when Kubernetes requests can be distinguished as coming from ROCK.

Written by the indexing model from the issue text.