Ship mcns.service, mcns-backup.service, mcns-backup.timer, and
deploy/scripts/install.sh adapted from MCR's deployment files.
Includes full security hardening block per engineering standards
and AmbientCapabilities=CAP_NET_BIND_SERVICE for DNS port 53.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
