Make production listener configurable

server.ts

@@ -12,7 +12,12 @@ const execAsync = promisify(exec);
 
 async function startServer() {
   const app = express();
-  const PORT = 3000;
+  const port = Number.parseInt(process.env.PORT ?? "3000", 10);
+  const host = process.env.HOST ?? "0.0.0.0";
+
+  if (!Number.isInteger(port) || port < 1 || port > 65535) {
+    throw new Error(`Invalid PORT value: ${process.env.PORT}`);
+  }
 
   app.use(express.json());
 
@@ -756,8 +761,8 @@ async function startServer() {
     });
   }
 
-  app.listen(PORT, "0.0.0.0", () => {
-    console.log(`Labyricorn Control Plane running on http://0.0.0.0:${PORT}`);
+  app.listen(port, host, () => {
+    console.log(`Labyricorn Control Plane running on http://${host}:${port}`);
   });
 }