added NLU v3 functionality with JSON schema validation and error handling in OpenAI service

src/app.js

@@ -10,7 +10,7 @@ export function createApp({ tenantId }) {
   const app = express();
 
   app.use(cors());
-  app.use(express.json({ limit: "1mb" }));
+    app.use(express.json({ limit: "1mb" }));
 
   // Serve /public as static (UI + webcomponents)
   const __filename = fileURLToPath(import.meta.url);