chore: fix clippy dead_code warning on handler.transport, update serve-loop task to completed

crates/wraith-core/src/server/handler.rs

@@ -48,6 +48,7 @@ pub struct ServerHandler {
     outbound_proxy: Option<ProxyConfig>,
     remote_addr: Option<SocketAddr>,
     control_channel_router: ControlChannelRouter,
+    #[allow(dead_code)]
     transport: TransportKind,
     connection_limiter: Arc<ConnectionRateLimiter>,
     connection_allowed: bool,