debug: log TUN read byte count

konduit-platform/src/tun.rs

@@ -185,7 +185,8 @@ impl TunDevice {
                         info!("TUN device closed");
                         break;
                     }
-                    Ok(_) => {
+                    Ok(n) => {
+                        debug!("TUN read: {} bytes", n);
                         if tun_pkt_tx.send(buf.freeze()).await.is_err() {
                             break;
                         }