The display-zone row for a user menu: a submenu of one-click zones, each
saved on select like the appearance row, and a search over every zone. A
phone has no room beside the menu for a submenu, so there the row opens the
search, which leads with the same zones. Mount it inside
DropdownMenuContent. The dialog stays inside the menu's React tree, so
working in it never dismisses the menu and unmounts it.
The display-zone row for a user menu: a submenu of one-click zones, each saved on select like the appearance row, and a search over every zone. A phone has no room beside the menu for a submenu, so there the row opens the search, which leads with the same zones. Mount it inside
DropdownMenuContent. The dialog stays inside the menu's React tree, so working in it never dismisses the menu and unmounts it.