/**
 * Where a page's social card lives.
 *
 * Shared, because the build writes the file and the prerendered `<head>` points at it — and
 * a card nothing references is a card nobody sees.
 */
export function ogImagePath(url: string): string {
  const clean = url.replace(/^\/+|\/+$/g, '');
  // A path per route, rather than a flattened filename: `/a/b` and `/a-b` are different
  // routes and must not write to the same file.
  return clean === '' ? '/api/og/card.png' : `/api/og/${clean}/card.png`;
}