Allows the notification server to keep critical notifications on top of e.g. fullscreen windows.
Hmm, looks okay to me though it probably won't work on Wayland (at least right now).
Please don't introduce such magic. If you need a special window type please add one or use osd directly. Please keep in mind that there's no way to set keep above for Wayland windows.
Will introduce a CriticalNotification window type then
I can make you a new layer if you want. There's also D18365 to make keep above work.