feat: artifacts

frontend/src/app/recollections/state/recollectionStore.ts

@@ -16,6 +16,19 @@ export type RenderOutputCacheEntry = {
   label: string
   type: 'image' | 'html'
   content: string
+  /** Timestamp (ms) when this entry was last updated. */
+  updatedAt?: number
+}
+
+/** Returns a short "time since" string for display (e.g. "Just now", "2 min ago"). */
+export function formatTimeSinceLastUpdate(updatedAt: number | undefined): string {
+  if (updatedAt == null || typeof updatedAt !== 'number') return ''
+  const delta = Date.now() - updatedAt
+  if (delta < 15_000) return 'Just now'
+  if (delta < 60_000) return `${Math.round(delta / 1000)}s ago`
+  if (delta < 3600_000) return `${Math.round(delta / 60_000)} min ago`
+  if (delta < 86400_000) return `${Math.round(delta / 3600_000)}h ago`
+  return `${Math.round(delta / 86400_000)}d ago`
 }
 
 export const RECOLLECTION_FILE_EXT = '.zui.json'