Implement limit check for linked items

Added a check for the maximum limit of linked items before moving an item from free_list to linked_list.

sources/ui/masterpropertieswidget.cpp

@@ -348,14 +348,32 @@ void MasterPropertiesWidget::headerCustomContextMenuRequested(const QPoint &pos)
 	@brief MasterPropertiesWidget::on_link_button_clicked
 	move current item in the free_list to linked_list
 */
+/**
+ * @brief MasterPropertiesWidget::on_link_button_clicked
+ * move current item in the free_list to linked_list
+ */
 void MasterPropertiesWidget::on_link_button_clicked()
 {
-		//take the current item from free_list and push it to linked_list
+	// --- NEU: Prüfen, ob das Master-Limit im UI bereits erreicht ist ---
+	QVariant max_slaves_variant = m_element->kindInformations().value("max_slaves");
+
+	if (max_slaves_variant.isValid() && !max_slaves_variant.toString().isEmpty()) {
+		int max_slaves = max_slaves_variant.toInt();
+
+		// Wir zählen, wie viele Elemente schon in der "Verbunden"-Liste liegen
+		if (max_slaves != -1 && ui->m_link_tree_widget->topLevelItemCount() >= max_slaves) {
+			// Limit erreicht! Wir brechen die Aktion einfach ab.
+			return;
+		}
+	}
+	// -------------------------------------------------------------------
+
+	//take the current item from free_list and push it to linked_list
 	QTreeWidgetItem *qtwi = ui->m_free_tree_widget->currentItem();
 	if (qtwi)
 	{
 		ui->m_free_tree_widget->takeTopLevelItem(
-					ui->m_free_tree_widget->indexOfTopLevelItem(qtwi));
+			ui->m_free_tree_widget->indexOfTopLevelItem(qtwi));
 		ui->m_link_tree_widget->insertTopLevelItem(0, qtwi);
 
 		if(m_live_edit)