feat: migrate frontend to Astro + expand AI moderation + backend admin/runtime config

Frontend:
- migrate from Vite to Astro (astro.config.mjs, pages/, layouts/)
- add admin panel, settings page, command palette, error boundary
- refactor App.tsx, MascotChatbot, Sidebar, Header, DashboardLayout
- update API client, WebSocket, auth, dashboard features

Backend:
- add admin module and config routes
- refactor middlewares, Redis connection, WebSocket server/bridge
- add runtime config loader

Discord Gateway:
- refactor AI moderation: circuit breaker, concurrency limiter, fallback processor
- add media analysis client, Seaxng search, user profile learner
- add new drizzle migration

Shared:
- extend database schema, add new config fields

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>
+  );
+}