Keep overlays sharp without parked surfaces (#14458)

* Keep overlays sharp without parked surfaces

* Refresh overlay monitor scale after live changes

* Reset menu layout when its monitor changes

test/acceptance.d/base-test.sh

@@ -81,17 +81,11 @@ layer_absent() {
   ! layer_present "$1"
 }
 
-# Overlays built on OverlayWindow (the menu, image selector, emoji picker,
-# clipboard and the like) stay mapped between opens, parked 1x1 on the bottom
-# layer, so they keep their fractional scale. Showing means on the overlay.
+# Fullscreen overlays map on the overlay layer and unmap when closed.
 layer_on_overlay() {
   hyprctl -j layers | jq -e --arg ns "$1" '[.[].levels["3"][]? | select(.namespace == $ns)] | length > 0'
 }
 
-layer_off_overlay() {
-  ! layer_on_overlay "$1"
-}
-
 # A layer can be mapped but parked off the monitor: the bar hides that way so
 # revealing it does not have to rebuild the surface. Assert on geometry when
 # what matters is that the user can actually see it. Layer boxes are local to