QA blocker: when the secondary-sdr container was down, the checkin omitted secondary_sdr_running / sdr_devices / op25_sdr_serial, and C2 only overwrites keys that are present, so the dashboard kept the last 'Running' forever. Send explicit nulls. The local card also says 'not reported' rather than 'not plugged in' for a pin it can't check. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>