Every cron job can now call cron-heartbeat-write.sh <job> <interval>
to write /var/run/bezalel/heartbeats/<job>.last atomically.
bezalel_heartbeat_check.py (meta-heartbeat) scans all .last files
every 15 minutes and alerts P1 if any job is stale > 2× its interval.
morning_report.py now includes a heartbeat panel showing the last-seen
status of every registered cron job in the nightly Night Watch report.
Systemd units (bezalel-meta-heartbeat.timer/.service) run the checker
on a 15-minute schedule via the poka-yoke infrastructure.
Fixes#1096
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
