Steam starts SteamVR 2.17 inside the Steam Linux Runtime (sniper)
container, which only sees the host's /usr under /run/host. vrserver then
skips /usr/share/steamvr-monado as "not a directory" and reports
HmdNotFound (#3).
The registration service now sets SteamVR's launch option to
vrmonitor.sh %command%, which starts SteamVR on the host. Steam rewrites
localconfig.vdf on exit, so the option is written only while Steam is
closed, and the service logs a restart hint until then. Custom launch
options are left alone. Uninstall removes only this option.
Fixes#3