/** getRandomValues also works on HTTP intranet pages where randomUUID is unavailable. */
export function newRequestId(): string {
  const bytes = globalThis.crypto.getRandomValues(new Uint8Array(16));
  bytes[6] = (bytes[6] & 15) | 64;
  bytes[8] = (bytes[8] & 63) | 128;
  const hex = Array.from(bytes, b => b.toString(16).padStart(2, "0")).join("");
  return `${hex.slice(0,8)}-${hex.slice(8,12)}-${hex.slice(12,16)}-${hex.slice(16,20)}-${hex.slice(20)}`;
}