export function truncateUtf8(value: string, maxBytes: number) {
  if (maxBytes <= 0) return "";
  if (Buffer.byteLength(value) <= maxBytes) return value;
  const buffer = Buffer.from(value);
  let end = Math.min(maxBytes, buffer.length);
  while (end > 0 && (buffer[end] & 0xc0) === 0x80) end--;
  return buffer.subarray(0, end).toString();
}