Add JettingProxy relay, convert Xpl2Client to active connection modelHEADmaster

Insert a transparent TCP proxy between the controller and N clients:
- JettingProxy listens on 9110-9112 (controller) and 9210-9212 (clients)
- Broadcasts controller frames to all clients, forwards client→controller
- Independent KA_PING handling on both sides

Convert Xpl2Client from passive QTcpServer listener to active QTcpSocket
outbound connections with auto-retry. New QML API: host/commandPort
properties, connectToProxy()/disconnectFromProxy() replacing
startListening()/stopListening().

1 files changed, 24 insertions, 15 deletions

diff --git a/jetting-interface/Main.qml b/jetting-interface/Main.qml
index 1c7b553..cd69ed8 100644
--- a/jetting-interface/Main.qml
+++ b/jetting-interface/Main.qml
@@ -31,9 +31,8 @@ ApplicationWindow {
 
     Connections {
         function onConnectedChanged() {
-            debugConsole.appendLog(Xpl2Client.connected
-                                   ? "Controller connected" :
-                                     "Controller disconnected");
+            debugConsole.appendLog(Xpl2Client.connected ? "Connected to proxy" :
+                                                          "Disconnected from proxy");
         }
 
         function onErrorOccurred(error: string) {
@@ -44,12 +43,6 @@ ApplicationWindow {
             statusPage.lastJcStatus = status;
         }
 
-        function onListeningChanged() {
-            debugConsole.appendLog(Xpl2Client.listening
-                                   ? "Listening on ports 9110/9111/9112" :
-                                     "Stopped listening");
-        }
-
         function onPhStatusReceived(status) {
             statusPage.lastPhStatus = status;
         }
@@ -101,9 +94,25 @@ ApplicationWindow {
             RowLayout {
                 anchors.fill: parent
 
+                TextField {
+                    Layout.preferredWidth: 140
+                    placeholderText: "Host"
+                    text: Xpl2Client.host
+
+                    onEditingFinished: Xpl2Client.host = text
+                }
+
+                TextField {
+                    Layout.preferredWidth: 70
+                    placeholderText: "Port"
+                    text: Xpl2Client.commandPort
+
+                    onEditingFinished: Xpl2Client.commandPort = parseInt(text)
+                }
+
                 Label {
-                    text: Xpl2Client.connected ? "Controller connected" :
-                                                 "Waiting for controller…"
+                    text: Xpl2Client.connected ? "Connected to proxy" :
+                                                 "Disconnected"
                 }
 
                 Item {
@@ -111,13 +120,13 @@ ApplicationWindow {
                 }
 
                 Button {
-                    text: Xpl2Client.listening ? "Stop" : "Listen"
+                    text: Xpl2Client.connected ? "Disconnect" : "Connect"
 
                     onClicked: {
-                        if (Xpl2Client.listening)
-                        Xpl2Client.stopListening();
+                        if (Xpl2Client.connected)
+                        Xpl2Client.disconnectFromProxy();
                         else
-                        Xpl2Client.startListening();
+                        Xpl2Client.connectToProxy();
                     }
                 }
             }