Add Makefile, demo agents, and Chinese README

[JinFanZheng]

Summary

• add Makefile shortcuts and update docker compose to run bundled demo agents, including healthcheck fix
• introduce LLM helper and Chinese poet agents with env-based configuration and document their usage
• provide Chinese README translation and refreshed contributor guidance referencing the new tooling

Testing

• Not run (documentation and configuration updates only)

[vercel]

@JinFanZheng is attempting to deploy a commit to the Raphael's projects Team on Vercel.

A member of the Team first needs to authorize it.

[zomux]

@pjymint Pls run pytest and check the makefile

[zomux]

Taking over.