R20F-R02 rollback guidance

#!/usr/bin/env bash
# Manual rollback only after explicit operator decision.
ssh pve-mgts "ssh -T -i /root/.ssh/pve_to_openwrt_mgts_ed25519 root@10.71.100.2 'R20F_BACKUP_DIR=/root/router-egress-r20f-backup-20260720-153640 sh -s'" < scripts/vm101-rollback.sh