Blank screen on idle / dpms
This is the shell side of phoc!60 (diffs) - the code itself works but we sometimes receive a spurious wakeup event from g-s-d right after lock that shouldn't be there which makes us unblank the screen again right away but then blank correctly a couple of seconds later.
Also we turn off the screen on initial startup as well (since we lock the screen) which is confusing UI wise so we have to separate lock from blank. This also helps when so we can e.g blank the screen without locking (e.g. on a longer phone call).
The pipelines will keep failing until we have updated phoc with the newer protocol.
As a bonus this makes us unblank the screen on keypress which is nice when running on laptops or with a keyboard attached.