More stringent caching mitigation

apps/backend/src/app/not-found.tsx

@@ -1,3 +1,13 @@
-export default function NotFound() {
-  return "Not Found";
+import { connection } from "next/server";
+
+export const dynamic = "force-dynamic";
+export const fetchCache = "force-no-store";
+export const revalidate = 0;
+
+export default async function NotFound() {
+  await connection();  // guarantees we will never prerender
+
+  return <div>
+    404 Not Found
+  </div>;
 }