exclusionMode was ExclusionMode.Ignore, which tells the compositor to
disregard the exclusive zone outright — so the expression below it computed
a height that was thrown away and every window laid out underneath the bar.
The bar is not app space while it is visible.
Auto-hide still yields 0, so a bar configured to hide gives its space back;
the mode only says "honour what I claim".
Not deployed: the phone locked itself on session start, which is
lock-on-startup firing for the first time under viewtop (80cb4b2), and
deploy.sh refuses a live deploy into a locked session.
ca272d1d7d