chore: code refactor

lib/time.ts

@@ -0,0 +1,19 @@
+/**
+ * Compact relative time ("just now", "5m ago", "3h ago", "2d ago"), falling
+ * back to a locale date for anything older than a week. Shared across the
+ * notification feed, the comments drawer, and anywhere else that shows a
+ * timestamp tail.
+ */
+export function timeAgo(iso: string): string {
+  const then = new Date(iso).getTime();
+  if (Number.isNaN(then)) return "";
+  const secs = Math.max(0, Math.floor((Date.now() - then) / 1000));
+  if (secs < 45) return "just now";
+  const mins = Math.floor(secs / 60);
+  if (mins < 60) return `${mins}m ago`;
+  const hours = Math.floor(mins / 60);
+  if (hours < 24) return `${hours}h ago`;
+  const days = Math.floor(hours / 24);
+  if (days < 7) return `${days}d ago`;
+  return new Date(iso).toLocaleDateString();
+}