feat(frontend): 4-zone shell + F1 loop end-to-end (MSW)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/App.tsx

@@ -1,3 +1,11 @@
+import { QueryClientProvider } from "@tanstack/react-query";
+import { queryClient } from "./app/queryClient";
+import { AppShell } from "./shell/AppShell";
+
 export function App() {
-  return <div className="p-4 text-lg font-semibold">ThothII</div>;
+  return (
+    <QueryClientProvider client={queryClient}>
+      <AppShell />
+    </QueryClientProvider>
+  );
 }