type PreviewVideo = Pick<HTMLVideoElement, 'paused' | 'srcObject' | 'muted' | 'play'>;

/** Restore browser presentation without changing the peer or camera capture. */
export function previewPlayback(video: PreviewVideo | null) {
 let disposed = false, pending = false;
 return {
  resume() {
   if (disposed || pending || !video?.srcObject || !video.paused) return;
   pending = true;
   video.muted = true;
   // WebKit can pause an offscreen panel and reject playback while it remains hidden.
   // A later visibility/presentation check retries playback on the same stream.
   void video.play().catch(() => undefined).finally(() => { pending = false; });
  },
  dispose() { disposed = true; },
 };
}