The trigger is an empty role="combobox" with no
aria-label, aria-labelledby, or associated
<label>; the placeholder is a separate
aria-hidden element. Per ARIA, a combobox does not take its name
from content, so it surfaces as a bare combobox. Bubblegum's
nameless-combobox fallback resolves it by role + uniqueness when the step
signals a dropdown (e.g. "Open the fruit dropdown").