@nprofile1q... You may use the /etc/hosts file if you're wanting to block sites from the device itself, problem being you'd most likely have to manually maintain it / add it as a nixOS package and then have to auto update your hosts.
@nprofile1q...@nprofile1q... Jellyfin also acts as a music server, which works great for me since there are many native clients on linux at least. On FreeBSD there's at least the official clients, probably some unofficial ones too but for sure will be more limited.