Rows are 40pt below md and 28pt above it. The split is on breakpoint rather
than presentation because the compact popover, which compactMode defaults to,
is worked with a thumb just as a sheet is.
Move vertical spacing off the row onto a new MenuPage, which also provides a
page's depth so the popover and the sheet cannot disagree about what a page is.
A row carrying vertical margin would serve both the edge inset and the
inter-row gap at once, and margins do not collapse.
Mohamed Boudra
56cb70fa59