Format Go code

[Francisca105]

Just like we currently do in the frontend, we want to enforce automatic code formatting in the Go backend before commits and during pull requests.

The goal is to introduce a tool (e.g., Husky, Lefthook, or another Git hook manager) that runs a Go formatter—such as:

gofmt -w ./...

This should ensure that:

• All Go files are automatically formatted before each commit, preventing unformatted code from entering the repository.

• Formatting is also validated in PRs, matching the existing frontend workflow and keeping code style consistent across the project.

We should evaluate the available tools and implement the one that best fits our environment.