The VM error persisted with polkit-kde installed: the package's autostart
.desktop carries OnlyShowIn=KDE;, so XDG autostart (which niri honors via
xdg-desktop-autostart.target) skips the agent in a niri session. Package
present, agent never running — exactly the observed behavior.
install_session_prereqs now rewrites the .desktop without the OnlyShowIn
line in place (idempotent: only rewrites when the line is present).
Pathfinder
6a9941771a