A nightly off-box backup older than 26 hours is a card on /flow with the one action that retries it #10924

A nightly off-box backup older than 26 hours is a card on /flow with the one action that retries it.

Done looks like:

• [x] an alarm module reads the newest successful off-box backup and raises at 26 h
• [x] the card names the last failure's cause in a line and offers one retry action
• [x] it clears when a backup succeeds; a test covers raise, clear and the cause line

Risks: retry must not run two backups at once; take the existing lock. Suits: torque

Files: src/flow/alarm_backup.ts, src/flow/alarms.ts, test/alarm-backup.test.ts

Reviewed pull #10933 at its head: ticked an alarm module reads the newest successful off-box backup and raises at 26 h; the card names the last failure's cause in a line and offers one retry action; it clears when a backup succeeds; a test covers raise, clear and the cause line.