feat(docs): add progress dashboard components and styling

apps/docs/lib/utils.ts

@@ -0,0 +1,7 @@
+import { type ClassValue, clsx } from "clsx";
+import { twMerge } from "tailwind-merge";
+
+/** shadcn's class combiner: conditional classes, later Tailwind utilities win. */
+export function cn(...inputs: ClassValue[]) {
+  return twMerge(clsx(inputs));
+}