export interface ExpandedImageItem {  src: string;  name: string;} export interface ExpandedImagePreview {  images: ExpandedImageItem[];  index: number;} export function getExpandedImagePreviewKey(preview: ExpandedImagePreview): string {  const selectedImage = preview.images[preview.index];  return `${preview.index}:${preview.images.length}:${selectedImage?.src ?? ""}`;} export function buildExpandedImagePreview(  images: ReadonlyArray<{ id: string; name: string; previewUrl?: string }>,  selectedImageId: string,): ExpandedImagePreview | null {  const previewableImages = images.flatMap((image) =>    image.previewUrl ? [{ id: image.id, src: image.previewUrl, name: image.name }] : [],  );  if (previewableImages.length === 0) {    return null;  }  const selectedIndex = previewableImages.findIndex((image) => image.id === selectedImageId);  if (selectedIndex < 0) {    return null;  }  return {    images: previewableImages.map((image) => ({      src: image.src,      name: image.name,    })),    index: selectedIndex,  };}