The scanner and monitor are mutually exclusive (both need the SDR).
Previously auto-monitor tried to start mid-scan (causing device
conflicts) and required 3 towers (rarely achieved with weak signals).
Now after the first scan completes:
- If any towers were found, automatically stop scanner and start
grgsm_livemon + tshark on the strongest tower's ARFCN
- SDR handoff is clean (scanner process has already exited)
- If monitor fails to start, scanner loop resumes
- Scanner thread's finally block preserves SDR allocation when
monitor has taken over
- Frontend shows "Monitoring ARFCN X for devices..." status
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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