XPL2 protocol foundation: wire framing, typed API, KA_PING, GS_JC_VERSION

Add Xpl2Protocol namespace with buildMessage/parseMessage for wire
serialization. Replace raw send/receive API on Xpl2Client with typed
protocol methods and internal dispatch. Auto-reply to KA_PING on all
sockets (qDebug only). Add GS_JC_VERSION as first typed command with
controllerId, firmwareVersion, hardwareVersion, printheadCount properties.

Upgrade mock server from echo to line-based command dispatch with 1s
KA_PING timer and canned GS_JC_VERSION response. Unknown commands
produce qWarning instead of echo.

Overhaul demo: remove raw send UI and port config, add wireDebug
toggle and Get JC Version button.

1 files changed, 36 insertions, 28 deletions

diff --git a/src/Xpl2Client.h b/src/Xpl2Client.h
index 7ce70ae..9212771 100644
--- a/src/Xpl2Client.h
+++ b/src/Xpl2Client.h
@@ -4,6 +4,8 @@
  */
 #pragma once
 
+#include "Xpl2Protocol.h"
+
 #include <QObject>
 #include <QQmlEngine>
 #include <QTcpSocket>
@@ -15,13 +17,15 @@ class Xpl2Client : public QObject
   QML_SINGLETON
 
   Q_PROPERTY (QString host READ host WRITE setHost NOTIFY hostChanged)
-  Q_PROPERTY (quint16 commandPort READ commandPort WRITE setCommandPort NOTIFY
-                  commandPortChanged)
-  Q_PROPERTY (quint16 imagingPort READ imagingPort WRITE setImagingPort NOTIFY
-                  imagingPortChanged)
-  Q_PROPERTY (quint16 statusPort READ statusPort WRITE setStatusPort NOTIFY
-                  statusPortChanged)
   Q_PROPERTY (bool connected READ isConnected NOTIFY connectedChanged)
+  Q_PROPERTY (
+      bool wireDebug READ wireDebug WRITE setWireDebug NOTIFY wireDebugChanged)
+  Q_PROPERTY (int controllerId READ controllerId NOTIFY jcVersionReceived)
+  Q_PROPERTY (
+      QString firmwareVersion READ firmwareVersion NOTIFY jcVersionReceived)
+  Q_PROPERTY (
+      QString hardwareVersion READ hardwareVersion NOTIFY jcVersionReceived)
+  Q_PROPERTY (int printheadCount READ printheadCount NOTIFY jcVersionReceived)
 
 public:
   explicit Xpl2Client (QObject *parent = nullptr);
@@ -29,52 +33,51 @@ public:
   QString host () const;
   void setHost (const QString &host);
 
-  quint16 commandPort () const;
-  void setCommandPort (quint16 port);
-
-  quint16 imagingPort () const;
-  void setImagingPort (quint16 port);
+  bool isConnected () const;
 
-  quint16 statusPort () const;
-  void setStatusPort (quint16 port);
+  bool wireDebug () const;
+  void setWireDebug (bool enabled);
 
-  bool isConnected () const;
+  int controllerId () const;
+  QString firmwareVersion () const;
+  QString hardwareVersion () const;
+  int printheadCount () const;
 
   Q_INVOKABLE void connectToServer ();
   Q_INVOKABLE void disconnectFromServer ();
-  Q_INVOKABLE void sendToCommandSocket (const QString &message);
-  Q_INVOKABLE void sendToImagingSocket (const QString &message);
-  Q_INVOKABLE void sendToStatusSocket (const QString &message);
+  Q_INVOKABLE void getJcVersion ();
 
 signals:
   void hostChanged ();
-  void commandPortChanged ();
-  void imagingPortChanged ();
-  void statusPortChanged ();
   void connectedChanged ();
-  void commandSocketResponseReceived (const QString &response);
-  void imagingSocketResponseReceived (const QString &response);
-  void statusSocketResponseReceived (const QString &response);
+  void wireDebugChanged ();
   void errorOccurred (const QString &error);
   void statusMessage (const QString &message);
+  void wireDebugMessage (const QString &message);
+  void jcVersionReceived ();
 
 private slots:
   void onCommandSocketConnected ();
   void onCommandSocketDisconnected ();
-  void onCommandSocketReadyRead ();
+  void onCommandSocketMessageReady ();
   void onCommandSocketError (QAbstractSocket::SocketError error);
   void onImagingSocketConnected ();
   void onImagingSocketDisconnected ();
-  void onImagingSocketReadyRead ();
+  void onImagingSocketMessageReady ();
   void onImagingSocketError (QAbstractSocket::SocketError error);
   void onStatusSocketConnected ();
   void onStatusSocketDisconnected ();
-  void onStatusSocketReadyRead ();
+  void onStatusSocketMessageReady ();
   void onStatusSocketError (QAbstractSocket::SocketError error);
 
 private:
-  void sendToSocket (QTcpSocket &socket, const QString &label,
-                     const QString &message);
+  void sendCommand (QTcpSocket &socket, const QByteArray &command,
+                    const QVariantList &params = {});
+  void dispatchCommandMessage (const Xpl2Protocol::ParsedMessage &msg);
+  void dispatchImagingMessage (const Xpl2Protocol::ParsedMessage &msg);
+  void dispatchStatusMessage (const Xpl2Protocol::ParsedMessage &msg);
+  void handleKaPing (QTcpSocket &socket);
+  void handleGsJcVersion (const QVariantList &params);
   void updateConnectedState ();
 
   QTcpSocket m_commandSocket;
@@ -85,4 +88,9 @@ private:
   quint16 m_imagingPort = 9111;
   quint16 m_statusPort = 9112;
   bool m_connected = false;
+  bool m_wireDebug = false;
+  int m_controllerId = 0;
+  QString m_firmwareVersion;
+  QString m_hardwareVersion;
+  int m_printheadCount = 0;
 };