Manages roving-tabindex focus and the WAI-ARIA tree keyboard model. ArrowUp/ArrowDown/Home/End roam linearly over the visible treeitems (skipping disabled ones), while ArrowRight/ArrowLeft carry tree semantics (expand/collapse, move to first-child/parent). Enter/Space activate, and printable characters trigger typeahead.
pnpm dlx shadcn@latest add "https://astryx.atmeta.com/shadcn/hook-use-tree-focus.json"