The standard sheet was sticky at `top: 0` and `100dvh` tall, so in an
installed app with a status bar its head row and close button slid under
the status bar once the page scrolled, where the modal sheet already
starts at `--material-safe-top`. Inside `<x-scaffold>` a sticky
`<x-app-bar>` in the `top` slot spans the content region, sheet and all,
and covered it the same way, safe area or not. The sheet now sticks at
`--drawer-top`, the top safe area, or under a scaffold's sticky bar that
safe area plus the bar's 64px row (just the row, if taller than the safe
area, for a medium or large bar, which collapses to it), and is as tall
as the window below that. Every side sheet keeps the bottom safe area
inside its bottom padding. A browser test scrolls a standard sheet in a
scaffold with no bar, a small bar and a large bar at a 47px top and 34px
bottom inset and measures where it sticks, its foot, its close button
and its padding; it fails without the change.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
