- uninstall: nix-installer's copy outside /nix is made and run as root
(a user-writable copy run by sudo could be swapped); README uninstall
paragraph shortened to one account of what happens when Nix stays.
- session.nix: the restart-check activation after steamFrameUserServices,
so the latter's comment is above it again.
- install.sh: a duplicate `local` in port_listening; comments.
- docs/cleanup.md: the installer internals of --clone (how an existing
clone is recognised, which git) and restart-check (what it compares,
test overrides); README keeps the usage.
- README install paragraph: shorter list of the dashboard patches.