[context menu] `ContextMenuTrigger` long-press doesn't fire for stylus input

Hi! `ContextMenuTrigger`'s long-press path uses TouchEvents (`onTouchStart`/`Move`/`End`/`Cancel`), so it doesn't fire for stylus input. Apple Pencil on iOS Safari dispatches PointerEvents only, and most Surface pen and Wacom-style tablet setups are pointer-primary too. Would you consider switching to PointerEvents filtered to `pointerType === 'touch' || pointerType === 'pen'`? The 500ms timer, 10px movement tolerance, and cancellation logic would all carry over unchanged for finger touch, and stylus users would get the same long-press UX.

Happy to send a PR if you'd accept it.