Containers: Start a Container at Boot with systemd

A site container was started by hand with podman run. It works now, but after the next reboot it won't be running. Make it a systemd service that starts the container at boot, either with a unit from podman generate systemd or a Quadlet file in /etc/containers/systemd/. The brief is in /root/case/brief.txt. This lab runs a systemd stand-in that reads real unit and Quadlet files, so systemctl enable, daemon-reload and a reboot behave as they do on RHEL. Lab machines have no internet access, so the image is already in podman's local store, as if you had pulled it.