/**
 * Focuses the page heading on route change. Mount once at a level that survives
 * navigation (e.g. `useRouteHeadingFocus(useLocation().pathname)`) and pass the
 * returned ref to `PageHeader`'s `titleRef`. The pending flag also catches
 * headings that mount after navigation; first render and StrictMode replays are no-ops.
 */
export declare function useRouteHeadingFocus(routeKey: string | number): (element: HTMLElement | null) => void;