The RNNoise config was deployed to /etc/xdg/pipewire, which PipeWire
never reads: it resolves $PIPEWIRE_CONFIG_DIR, then the home config, then
its compiled-in /etc/pipewire, and knows nothing of XDG_CONFIG_DIRS. An
installed system therefore had no denoising while carrying the file.
It now goes through services.pipewire.configPackages, with the LADSPA
plugin substituted to its store path since LADSPA_PATH has no /usr here.
Alongside, on the desktop host only: steam via its module (which also
turns on 32-bit graphics), bitwig-studio, and rtkit so a DAW can ask for
realtime scheduling at all.