/** 32 random bytes, base64url, no padding (43 characters) — a fresh `PREVIEW_SITES[key].linkKey`. */
export function newLinkKey(): string;

export function mintPreviewToken(o: {
  linkKey: string;
  siteKey: string;
  ttlSeconds: number;
  now?: number;
}): Promise<{ token: string; exp: number }>;

export function verifyPreviewToken(o: {
  linkKey: string | null | undefined;
  siteKey: string;
  token: string;
  now?: number;
}): Promise<boolean>;