Standard FreeBSD (and Linux) approach is to use
chsh command. However, that command is not present in NAS4Free. Fortunately, there is an alternative choice.
pw offers that and much more. To change shell, we simply execute the following command:
# pw user mod root -s /bin/bash
While we cannot make this default, we can add it under
Command Scripts. If we add this command as Post Init script, the next login will greet us with bash prompt.