Function tailscale_server_sans 

pub async fn tailscale_server_sans(
    tunnel: &TunnelConfig,
    wss: &WssConfig,
    enroll: &EnrollConfig,
) -> TailnetSans

Resolve the tailnet names for the daemon’s self-TLS listeners (WSS, enrollment). Queries tailscaled only when the listeners are reached over the tailnet. Callers that start several listeners must resolve once and share the outcome, so every listener presents the same identity.