feat(frontend): staggered list reveals + toast tone accents (level 5 polish)

services/frontend/src/lib/utils.ts

@@ -4,3 +4,10 @@ import { twMerge } from "tailwind-merge";
 export function cn(...inputs: ClassValue[]) {
   return twMerge(clsx(inputs));
 }
+
+/** Inline `animationDelay` for staggered list reveals. Pair with the
+ * `animate-stagger` class on the item root. steps=45ms, capped at 600ms so
+ * long lists don't drag the reveal out. */
+export function staggerDelay(i: number, step = 45, max = 600) {
+  return { animationDelay: `${Math.min(i * step, max)}ms` };
+}