feat(codex): Cursor compatibility + Next.js 16 proxy migration

- Force streaming for Codex/OpenAI models to fix non-streaming bug
- Strip unsupported params (user, metadata, stream_options, prompt_cache_retention)
- Force response translation from openai-responses to openai format
- Migrate middleware.js to proxy.js for Next.js 16
- Use webpack explicitly in dev/build scripts
- Updated Codex User-Agent

src/app/(dashboard)/dashboard/endpoint/EndpointPageClient.js

@@ -19,7 +19,7 @@ export default function APIPageClient({ machineId }) {
   const [showCloudModal, setShowCloudModal] = useState(false);
   const [showDisableModal, setShowDisableModal] = useState(false);
   const [cloudSyncing, setCloudSyncing] = useState(false);
-  const [setCloudStatus] = useState(null);
+  const [cloudStatus, setCloudStatus] = useState(null);
   const [syncStep, setSyncStep] = useState(""); // "syncing" | "verifying" | "disabling" | ""
 
   const { copied, copy } = useCopyToClipboard();