make verify-n8n / deploy/verify-n8n-scheduled-run.sh checks the workflow is
active, reads the newest scheduled (mode=trigger) execution from the n8n
database, and prints the notify rows. Exit 1 until a scheduled run exists and
is green, so it distinguishes 'not yet' from 'failed'. Never runs the workflow
and never sends. Document the first-run time and the re-armed monitor.