Re-enable Arcjet in server.js

[EcstaticFly]

During development I disabled the Arcjet in server.js because it was not accepting request from react native app in simulator and returned "403 bot detection error" for each and every type of simulator and postman request.
So, commented it out temporarily and will reactivate once react native frontend is complete and integrated correctly with backend. I did not want to run server locally with arcjet disabled and test everything on deployed url only.