/**
 * Modal keyboard a11y (#124), shared by every ModalProvider dialog:
 *
 * - **Focus restore**: remembers what was focused when the dialog opened and
 *   returns focus there on close, so keyboard users aren't dumped at the top of
 *   the desktop.
 * - **Focus trap**: Tab / Shift+Tab cycle within the dialog and never escape to
 *   the desktop behind it (also the XP behavior — the parent is inert, DLG-01).
 * - **Esc = cancel**: routed to the dialog's cancel action.
 *
 * Initial focus stays with each dialog (it already focuses its default control).
 * Attach `containerRef` to the dialog's overlay and spread `onKeyDown` on it.
 */
export declare function useModalA11y(onCancel?: () => void): {
    containerRef: React.RefObject<HTMLDivElement>;
    onKeyDown: (e: React.KeyboardEvent) => void;
};