Replaces a scaffold that rendered bare anchors. Flat or nested to three
levels, icons, badges, disabled items, aria-current on the active link,
arrow-key roving focus, and a disclosure arrow that rotates on open.
Three levels rather than arbitrary depth because this template language has
no component recursion, so each level is written out.
On a phone the bar becomes a toggle and submenus stack inline rather than
floating: a hover-opened overlay cannot be reached on touch.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>