Backups menu. Per site: the latest backup, its status (ok, outdated, failed, running, none yet), size and how many are kept, with “Back up now” and a link to restore. A “Backup” column in the site list.
Healthy means nothing to do right now. Acknowledged notices no longer count. A failed last backup counts as “action needed”.
Visual comparison against both baselines. A page that renders slightly differently on every load (for example a post list on mobile) no longer holds back a harmless update.