generateToken() now returns (string, error) instead of panicking on
crypto/rand failure. All json.Unmarshal calls for alert settings now
check and propagate errors instead of silently ignoring them.
Adds Close() to Store interface for graceful shutdown support.
Skips malformed notification entries during Kuma import.
Convert Kuma monitorList/notificationList to go-upkeep Backup format.
Maps all monitor types (http, ping, port, dns, group), ntfy notifications
with auth, parent IDs, and alert assignments. Available via --import-kuma
flag and POST /api/import/kuma endpoint.