Function host_for_daemon 

pub fn host_for_daemon(
    id: &DaemonId,
    config: Option<&PitchforkTomlDaemon>,
    global_slugs: &IndexMap<String, SlugEntry>,
) -> Option<String>

The hostname to advertise for a daemon: a legacy [slugs] entry when one exists, otherwise the automatic hostname.

Legacy slugs win because the proxy resolves them first, so this never advertises an address that routes somewhere else.