Function update_login_status 

fn update_login_status(
    message: &TcpClientMessage,
    old_token: Option<SessionID>,
    tx_channel: &Sender<TcpServerMessage>,
    connection_id: u64,
) -> Option<SessionID>

Evaluates authentication-related client messages (Login, Relogin, Logout) and updates global session states (via return).

Arguments

• message - The incoming client message payload.
• old_token - The existing session token associated with this connection context, if any.
• tx_channel - The transmission channel to send immediate auth feedback.
• connection_id - The unique identifier of the connection.