desktop notifications

we do already attempt to call notify-send: https://gitlab.com/jokeyrhyme/healthcheck/-/blob/main/bin/healthcheck-report.sh#L20
however, as this is run in the context of a systemd system service/unit, it likely doesn't know which interactive desktop dbus session to use
it almost certainly has permissions, as it is running as a root user
might be missing environment variables to know which dbus session?
perhaps the report unit needs to be a systemd user/session service instead?
might also be a bug in the way the report script is written?