android: what a screen reader says — names, roles, and the sheets out of the tree when they are down

Every control on the phone has a name now, in the app's own words, and the
desktop's word where it already has one; the nav is a tab set whose badge
count is part of the tab's name — "You, 3 transfers" rather than a stray 3
read out before it. The two sheets are dialogs with somewhere sensible for
the focus to land, and the half sheet's grab handle is finally a real
Close — the first dismissal a screen reader could reach, because the scrim
never was one. A sheet that is down is inert rather than sitting
off-screen in the accessibility tree with the hidden mini bar and the nav
under it, and one live region is mounted for the life of the app so that
an undo offer is actually announced; switches say on or off, chips say
pressed, and the waveform is a slider where it can seek. Nothing visible
changed. The walk counts the controls with no name, with a junk name, in a
hidden layer, or with unsaid state — all four held at zero on ten screens,
and the nameless count on a room and on both prompts besides, which is
where the six fields named here actually live.