Collect, clear, or list HarmonyOS device logs via hdc shell hilog.

Use this tool for runtime evidence during debugging of HarmonyOS applications.

Actions:
- collect: Fetch recent device logs, filtered by prefix
- clear: Clear the device log buffer
- list_devices: List connected HarmonyOS devices

Call this tool:
- When debugging runtime issues on HarmonyOS devices
- To collect logs before and after reproducing a bug
- To verify log output after code changes

Do NOT call this tool:
- For static code analysis (use grep or read instead)
- When no device is connected