Gate elevator descent on arm safety state

[ZenoCoding]

Summary

• track the requested elevator goal separately from the clamped target and re-evaluate limits each loop
• hold the carriage at the arm-safe boundary until the arm allows descending further, instead of blindly clamping once
• surface the pending request and arm-allowance flags on telemetry for easier debugging

Testing

• ./gradlew build

---

https://chatgpt.com/codex/tasks/task_e_68f9cbf21fb883248c987290795abbb5