Update vite.config.ts

Author: LCSOGthb

artifacts/mockup-sandbox/vite.config.ts

@@ -7,11 +7,7 @@ import { mockupPreviewPlugin } from "./mockupPreviewPlugin";
 
 const rawPort = process.env.PORT;
 
-if (!rawPort) {
-  throw new Error(
-    "PORT environment variable is required but was not provided.",
-  );
-}
+const port = Number(process.env.PORT ?? 5173);
 
 const port = Number(rawPort);