feat(web): richer active-job rows on The Floor (source/format/tracks, stage, elapsed, error)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/app/_ui/status.ts

@@ -15,6 +15,20 @@ const STATE_MAP: Record<string, { label: string; kind: Kind }> = {
   needs_attention: { label: "Needs attention", kind: "attention" },
 };
 
+/** Compact elapsed label from an ISO/Date string to `now` (ms since epoch). */
+export function timeAgo(value: string | Date | null | undefined, now: number): string {
+  if (!value) return "";
+  const t = new Date(value).getTime();
+  if (Number.isNaN(t)) return "";
+  const s = Math.max(0, Math.floor((now - t) / 1000));
+  if (s < 60) return "just now";
+  const m = Math.floor(s / 60);
+  if (m < 60) return `${m}m`;
+  const h = Math.floor(m / 60);
+  if (h < 24) return `${h}h`;
+  return `${Math.floor(h / 24)}d`;
+}
+
 export function describeJob(
   state: string,
   stage: string,