export function formatDuration(seconds: number): string {
  const h = Math.floor(seconds / 3600);
  const m = Math.floor((seconds % 3600) / 60);
  const s = seconds % 60;
  if (h > 0) return `${h}u ${m}m`;
  if (m > 0) return `${m}m ${s}s`;
  return `${s}s`;
}
export function formatPct(n: number): string { return `${Math.round(n * 100)}%`; }
export function formatDate(unixSec: number): string {
  return new Date(unixSec * 1000).toLocaleString();
}