Since the _frigate.service_ unit depends on _dev-apex_0.device_,
`/dev/apex_0` needs to have the `systemd` "tag" on its udev device info.
Without this tag, systemd will not "see" the device and thus will not
mark the `.device` unit as active.
Frigate is an NVR that uses machine learning to detect objects on camera
in real time. It integrates with Home Assistant to expose sensors which
can be used for automation, etc.
The only official way to deploy Frigate is with a container, so we use
Podman and systemd to manage it.