Add simple agent health check example

[xelons79]

Adds a minimal script to validate agent startup behavior.

---

Note

Adds a minimal example to verify agent startup and a no-op cycle.

• Introduces examples/agent_health_check.py with agent_health_check() and a CLI entrypoint that prints "Agent status: OK"

^{Written by Cursor Bugbot for commit 5bc5c1f. This will update automatically on new commits. Configure here.}