Rename classes to OpcUa* prefix, replace BobinkNode with OpcUaMonitoredNode boilerplate

Rename BobinkAuth → OpcUaAuth, BobinkClient → OpcUaClient (C++ class
names only; QML module URI and singleton name stay as Bobink).
Remove BobinkNode (QQuickItem-based) and add OpcUaMonitoredNode
skeleton using QObject + QQmlParserStatus, following Qt convention
for non-visual QML types.

1 files changed, 2 insertions, 110 deletions

diff --git a/demo/NodePage.qml b/demo/NodePage.qml
index fd81db5..bd57583 100644
--- a/demo/NodePage.qml
+++ b/demo/NodePage.qml
@@ -1,6 +1,4 @@
-// NodePage.qml — Monitors a single OPC UA node.
-// Two instances demonstrate visibility lifecycle: switching pages
-// stops monitoring on the hidden page automatically.
+// NodePage.qml — Placeholder while OpcUaMonitoredNode is implemented.
 
 import QtQuick
 import QtQuick.Controls
@@ -14,24 +12,6 @@ Page {
     required property int pageNumber
     required property var logFunction
 
-    property string monitoredNodeId: ""
-    property string nodeDescription: ""
-    property bool nodeWritable: true
-    property bool metadataLoaded: false
-
-    BobinkNode {
-        id: node
-        nodeId: nodePage.monitoredNodeId
-        onAttributeRead: (name, val) => {
-            if (name === "DisplayName")
-                nodePage.nodeDescription = val.toString();
-            else if (name === "AccessLevel")
-                nodePage.nodeWritable = (val & 0x02) !== 0;
-            nodePage.metadataLoaded = true;
-        }
-        onWriteError: (message) => nodePage.logFunction("WRITE: " + message)
-    }
-
     ColumnLayout {
         anchors.fill: parent
         anchors.margins: 20
@@ -50,96 +30,8 @@ Page {
             }
         }
 
-        RowLayout {
-            TextField {
-                id: nodeIdField
-                Layout.fillWidth: true
-                placeholderText: "ns=2;s=Temperature"
-                enabled: !nodePage.monitoredNodeId
-            }
-            Button {
-                text: nodePage.monitoredNodeId ? "Stop" : "Monitor"
-                onClicked: {
-                    if (nodePage.monitoredNodeId) {
-                        nodePage.monitoredNodeId = "";
-                        nodePage.nodeDescription = "";
-                        nodePage.nodeWritable = true;
-                        nodePage.metadataLoaded = false;
-                    } else {
-                        nodePage.monitoredNodeId = nodeIdField.text;
-                        node.readAttribute("DisplayName");
-                        node.readAttribute("AccessLevel");
-                    }
-                }
-            }
-        }
-
-        GroupBox {
-            Layout.fillWidth: true
-            visible: nodePage.monitoredNodeId.length > 0
-            title: nodePage.nodeDescription || nodePage.monitoredNodeId
-
-            GridLayout {
-                columns: 2
-                width: parent.width
-
-                Label { text: "Value:" }
-                Label {
-                    text: node.value !== undefined ? node.value.toString() : "—"
-                    font.family: "monospace"
-                    font.bold: true
-                }
-
-                Label { text: "Status:" }
-                Label {
-                    text: node.status === BobinkNode.Good ? "Good"
-                        : node.status === BobinkNode.Uncertain ? "Uncertain"
-                        : "Bad"
-                    color: node.status === BobinkNode.Good ? "green"
-                         : node.status === BobinkNode.Uncertain ? "orange"
-                         : "red"
-                }
-
-                Label { text: "Source TS:" }
-                Label {
-                    text: node.sourceTimestamp.toLocaleString(
-                              Qt.locale(), "HH:mm:ss.zzz")
-                    font.family: "monospace"
-                }
-
-                Label { text: "Server TS:" }
-                Label {
-                    text: node.serverTimestamp.toLocaleString(
-                              Qt.locale(), "HH:mm:ss.zzz")
-                    font.family: "monospace"
-                }
-            }
-        }
-
-        RowLayout {
-            visible: nodePage.monitoredNodeId.length > 0
-
-            TextField {
-                id: writeField
-                Layout.fillWidth: true
-                enabled: nodePage.nodeWritable
-                placeholderText: nodePage.metadataLoaded && !nodePage.nodeWritable
-                                 ? "Read-only node" : "Value to write"
-            }
-            Button {
-                text: "Write"
-                enabled: nodePage.nodeWritable
-                onClicked: {
-                    node.value = writeField.text;
-                    writeField.clear();
-                }
-            }
-        }
-
         Label {
-            visible: nodePage.monitoredNodeId.length > 0
-                     && nodePage.metadataLoaded && !nodePage.nodeWritable
-            text: "Read-only node"
+            text: "Node monitoring not yet available (OpcUaMonitoredNode in progress)"
             font.italic: true
             color: "gray"
         }