async function retry(fn, attempts = 5, base = 300) {
  for (let n = 0; n < attempts; n++) {
    try {
      return await fn();
    } catch (err) {
      if (n === attempts - 1) throw err;
      const wait = base * 2 ** n + Math.random() * 100;
      await new Promise((r) => setTimeout(r, wait));
    }
  }
}