- Updated all authentication commands to use `fmt` instead of `log` for errors, info, and success messages.
- Ensured message formatting aligns across commands for consistent user experience.
- Updated all `github.com/luispater/CLIProxyAPI/internal/...` imports to point to `github.com/luispater/CLIProxyAPI/v5/internal/...`.
- Adjusted `go.mod` to specify `module github.com/luispater/CLIProxyAPI/v5`.