/**
 * Storybook: Chromium exposes `documentPictureInPicture` as a read-only getter; assigning a mock
 * throws. obi-chat-web checks `window.__obiSdkStorybookDocumentPip` first and uses this iframe-based
 * `requestWindow` so "Host Layout Document PiP" can run without real OS PiP.
 */
export type StorybookDocumentPipBridge = {
    requestWindow: (opts: {
        width: number;
        height: number;
    }) => Promise<Window>;
};
declare global {
    interface Window {
        __obiSdkStorybookDocumentPip?: StorybookDocumentPipBridge;
    }
}
export declare function installStorybookDocumentPipShim(options: {
    /** Full-bleed story root; faux PiP iframe is absolutely positioned inside it */
    getMountSurface: () => HTMLElement | null;
}): () => void;
