export function externalUrl(request: Request, pathname: string) {
  const current = new URL(request.url);
  const host = request.headers.get("x-forwarded-host") || request.headers.get("host") || current.host;
  const protocol = request.headers.get("x-forwarded-proto") || current.protocol.replace(":", "");
  return new URL(pathname, `${protocol}://${host}`);
}