Add StoreKit history and modernize admin console

Expose ledger-backed cross-device purchase history while shipping the tested React admin redesign in the same reproducible deployment revision.

admin-web/src/lib/utils.ts

@@ -0,0 +1,6 @@
+import { clsx, type ClassValue } from "clsx";
+import { twMerge } from "tailwind-merge";
+
+export function cn(...inputs: ClassValue[]): string {
+  return twMerge(clsx(inputs));
+}