backup-postgres.sh now writes files[], one entry per archived host
directory (la-compagnie-maximus#295). sanitizeBackupsStatus() dropped
it as an unknown field, so a failed archive turned the status red with
no cause. It is now rebuilt from a whitelist like databases[], with a
closed code list of its own (source_missing, archive_failed,
encrypt_failed, invalid_name), the script's name pattern with a 63 cap,
a nullable archivedAt and a bound of 16. A status without files keeps
working.
Refs #61
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>