fix: update nginx config to use docker service name for upstream

[di3n0]

Problem

The frontend container was failing to connect to the backend (502 Bad Gateway) because 127.0.0.1 inside a container refers to the container itself, not the backend service.

Solution

Updated the Nginx proxy_pass to use the Docker Compose service name verifywise_backend_1 instead of localhost or 127.0.0.1. This allows Docker's internal DNS to correctly route the traffic.

Testing

Verified locally that the login request at http://localhost:8080/login no longer returns a 502 error and correctly communicates with the backend API.

[MuhammadKhalilzadeh]

Thank you so much @di3n0
Your code seems nothing wrong and looks good. Only that since it's on your repository, We're not able to run directly - but that's fine for such a small piece.
I'll also wait for my teammates @HarshP4585 and @Br0wnHammer to check (Download your code and test) as well