Update byte skipping logic and improve clarity in MeshCoreConnector and ChannelMessage

lib/connector/meshcore_connector.dart

@@ -4323,7 +4323,8 @@ class MeshCoreConnector extends ChangeNotifier {
           routeType == _routeTransportFlood ||
           routeType == _routeTransportDirect;
       if (hasTransport) {
-        reader.skipBytes(2); // Skip reserved bytes in transport header
+        // Skip reserved bytes in transport header made up of two u16 fields
+        reader.skipBytes(4);
       }
       final pathLenRaw = reader.readByte();
       final pathByteLen = _decodePathByteLen(pathLenRaw);

lib/models/channel_message.dart

@@ -129,11 +129,11 @@ class ChannelMessage {
       if (code == respCodeChannelMsgRecvV3) {
         reader.skipBytes(1); // Skip SNR
         final flags = reader.readByte();
+        final hasPath = (flags & 0x01) != 0;
         reader.skipBytes(1); // Skip reserved byte
         channelIdx = reader.readByte();
         pathLen = reader.readByte();
         txtType = reader.readByte();
-        final hasPath = (flags & 0x01) != 0;
         if (hasPath && pathLen > 0) {
           reader.rewind(); // Rewind to read path length again for pathBytes
           pathBytes = reader.readBytes(pathLen);

lib/services/message_retry_service.dart

@@ -678,7 +678,7 @@ class MessageRetryService extends ChangeNotifier {
     }
   }
 
-  String? getContactKeyForAckHash(Uint8List ackHash) {
+  String? getContactKeyForAckHash(int ackHash) {
     for (var entry in _pendingMessages.entries) {
       final message = entry.value;
       if (message.expectedAckHash != null &&