feat: wrapup wow — animated counters, scroll-reveal, fun facts, component split, budget formatting

spa/src/lib/format.ts

@@ -0,0 +1,6 @@
+export function fmtUsd(n: number): string {
+  if (n >= 1_000_000_000) return `$${(n / 1_000_000_000).toFixed(n % 1_000_000_000 === 0 ? 0 : 1)}B`
+  if (n >= 1_000_000) return `$${Math.round(n / 1_000_000)}M`
+  if (n >= 1_000) return `$${Math.round(n / 1_000)}K`
+  return `$${n}`
+}