The searchable choice put its `anchor-name` on a `<div>` around its
field, and menu.css sizes the popover list with
`anchor-size(width)`. The wrapper fills its container, but from
`medium` the field inside it stops at 40rem, so in a wider pane the
list ran past the field's end across the whole container: 1168px under
a 640px field. Found while giving the choice `full`, which only hid it.
The field itself carries the anchor now and the wrapper is gone, so the
list is as wide as the field, bounded or `full`, and still hangs under
the field's supporting text as before.
A browser test opens a bounded and a `full` searchable choice in a
1200px column and compares each list's width and start with its field;
it fails without the change in Chrome, Firefox and Safari.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
