Carries the display-corner inset (previous commit) through the three screens
that pin the same legend pill — settings, add-host, pair — so they don't drift
from the launcher the moment the user opens one. Each of those trays is
`maxWidth: .infinity, alignment: .leading`, so the pill is left-aligned there
too and the iPad's short centre indicator is never in its way; the keyboard
tray sits ABOVE the legend in the stack, so pulling the tray down doesn't put
keycaps over the strip.
And the settings tab strip now takes its padding from the row metrics instead
of two fixed numbers. It was the other half of the iPad sizing complaint: the
tier work grew the fields under it while the tab pills stayed at phone scale,
which read as a tab bar that belonged to a different screen.
macOS + tvOS typecheck.
Re-landed on the probe spelling: the corner inset is read from
`\.displayBottomInset` (DisplayBottomInsetProbe via ContentView), never asked
of UIKit during body — the original spelling froze the update graph of any
view that called it on device (see the legend-pinning commit).
enricobuehler
3daead7d71