granted registry add, sync, remove, and setup always read/write ~/.aws/config, ignoring the AWS_CONFIG_FILE environment variable.

The assume command was fixed for this in #229, but the registry commands still use a hardcoded path in pkg/granted/registry/ini.go.

cfaws.GetAWSConfigPath() already handles this correctly — the registry code just doesn't use it.

Expected: registry commands should respect AWS_CONFIG_FILE, same as assume does and consistent with AWS CLI behavior.