Revert "feat: migrate frontend to Astro SSG with design system"

This reverts commit 8ad888da28.

services/frontend/src/App.client.tsx

@@ -0,0 +1,18 @@
+// ─── App.client.tsx — Astro React island entry point ────────────────────────
+// DILOAD OLEH Astro client:only="react"
+// Menyediakan <div id="root"> dan mount App dengan provider yang diperlukan
+// ─────────────────────────────────────────────────────────────────────────────
+
+import React from "react";
+import App from "./App";
+import { ToastProvider } from "./shared/ui";
+
+export default function AppClient() {
+  return (
+    <React.StrictMode>
+      <ToastProvider>
+        <App />
+      </ToastProvider>
+    </React.StrictMode>
+  );
+}