- Add backup-b2-failed oneshot for OnFailure notification
- Add onFailure handler to both backup-b2 and backup-b2-check
- Add network-online.target dependency to backup-b2-check
- Add TimeoutStartSec (2h for backup, 1h for check)
Found via ops-review lenses.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Closes r177. Critical DR gap - user home directories and ACME
certificates were not being backed up.
Excludes common caches that can be rebuilt:
- .cache, .npm/_cacache, .bun/install/cache
- node_modules, .nix-profile, .nix-defexpr
- Trash
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>