Tracks the active option of a multi-select combobox and handles its keys, while DOM focus stays on the control. It powers MultiSelector; unlike useCombobox, toggling an option keeps the list open, and rows can carry an action cell. It renders nothing and sets no attributes: the caller renders the control and the list, and wires the ARIA attributes from what it returns.
pnpm dlx shadcn@latest add "https://astryx.atmeta.com/shadcn/hook-use-multi-combobox.json"