Menu entries are left-aligned and live in a ScrollContainer capped at 320 px, so a
long list (the parent picker holds every object of the scene) scrolls instead of
running off the screen. `Menu(items, { searchable: true })` puts a filter box above
the scroll area; Enter takes the first match. Filtering forces a relayout because
two queries with the same hit count leave the height unchanged, which would keep
the stale row positions.
Fields that open a menu are a new `Dropdown` widget: the value sits flush left and
the chevron is drawn flush right instead of being written into the label. A menu
opened below a field is never narrower than that field.
New debug hooks `overlayTexts()` / `overlayRect()` make the popup contents
assertable; e2e step 11 covers the cap, the scrolling and the search box.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
