Where a launched program runs (§6). overlay covers the caller's own region with opaque host chrome; stage replaces the focal app (the elevated into- stage surface, §7 — refused above the stage-principal ceiling).
overlay
stage
Where a launched program runs (§6).
overlaycovers the caller's own region with opaque host chrome;stagereplaces the focal app (the elevated into- stage surface, §7 — refused above the stage-principal ceiling).