/** "1.4 MB" — a byte count for people. Binary units, one decimal under 10. */
export function formatBytes(n: number): string {
  if (n < 1024) return `${n} B`;
  const units = ["KB", "MB", "GB", "TB"];
  let v = n / 1024, i = 0;
  while (v >= 1024 && i < units.length - 1) { v /= 1024; i++; }
  return `${v.toFixed(v >= 10 || i === 0 ? 0 : 1)} ${units[i]}`;
}