/**
 * Give an element focus without letting the page jump to it.
 *
 * Focusing normally asks the browser to bring the element into view, and that
 * is the right default for a page's own content. It is never right here: the
 * widget is `position: fixed` and already where the reader can see it, so any
 * scrolling that happens is the page being yanked around for nothing.
 *
 * It looks like it could not happen — a fixed box is always in view — but the
 * moment an ancestor has a `transform`, a `filter`, or `will-change` (an
 * animation wrapper, a page-transition container, half of the SPA shells out
 * there), `fixed` is measured against that ancestor instead of the viewport.
 * The widget then sits wherever that box ends, which may be thousands of
 * pixels down the document, and opening the panel scrolls the reader there.
 * The same happens inside an iframe, where the outer page scrolls the frame
 * into view.
 *
 * `preventScroll` says exactly that, and every browser this library supports
 * honours it. The reading and restoring around it is for the ones that do not:
 * the scroll they cause is synchronous, so putting the positions back on the
 * same turn means nothing is ever painted in the wrong place.
 *
 * @param {HTMLElement | null | undefined} element
 * @returns {boolean} True when there was something to focus.
 */
export function focusWithoutScrolling(element: HTMLElement | null | undefined): boolean;