Function select_item_pointer_up_handler 

pub fn select_item_pointer_up_handler(
    open: Model<bool>,
    value: Model<Option<Arc<str>>>,
    item_value: Arc<str>,
    item_disabled: bool,
    mouse_open_guard: SelectMouseOpenGuard,
) -> OnPointerUp

Returns an item-level pointer-up handler that respects the “open via mouse pointerdown” guard.

When a select is opened on mouse pointerdown, the click-release pointerup can land on top of the content. Radix installs a one-shot pointer-up guard to ensure that release does not immediately select an item. This helper mirrors that behavior for listbox options.