add ENV var for api endpoint for frontend

frontend/src/utils/constants.js

 export const API_BASE =
-  import.meta.env.VITE_ENABLE_GOOGLE_AUTH || "http://localhost:5000";
+  import.meta.env.VITE_API_BASE || "http://localhost:5000";

package.json

@@ -15,7 +15,7 @@
     "dev:server": "cd server && yarn dev",
     "dev:frontend": "cd frontend && yarn start",
     "prod:server": "cd server && yarn start",
-    "prod:frontend": "cd frontend && yarn start"
+    "prod:frontend": "cd frontend && yarn build"
   },
   "private": false
 }
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