KlipperScreen crashes on klix-update

[camelpunch]

[camelpunch]

Restarting cage brings it back to life - we're missing a systemd trigger.

[camelpunch]

Not a systemd trigger, because Cage+KlipperScreen are one unit. Might be worth a full nixpkgs update first, which really means we need a staging system now that we posted release messages.

[camelpunch]

Nixpkgs update didn't have an effect, despite there being at least one patch that prevented crashes. Putting this down to focus on loginless.