Rock-solid two-part backup (data directory + OpenDentImages) using the
cold-copy method: stop the DB service, verify it stopped, copy the whole
data dir (incl InnoDB ibdata1/ib_logfile*), then always restart the
service via a finally block. Covers mysqldump supplement, scheduling,
test-restore verification, and 3-2-1 retention.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
