Initial scaffold: React+TS+Vite frontend, FastAPI backend, config system

frontend/src/App.tsx

@@ -0,0 +1,13 @@
+import { useEffect } from 'react';
+import { useConfigStore } from '@/stores/configStore';
+import { AppShell } from '@/components/layout/AppShell';
+
+export default function App() {
+  const loadConfig = useConfigStore((s) => s.loadConfig);
+
+  useEffect(() => {
+    loadConfig();
+  }, [loadConfig]);
+
+  return <AppShell />;
+}