refactor(cpn): introduce BoundedString<N> for ModelData string fields (#7438)

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

companion/src/print/comparedialog.cpp

@@ -123,7 +123,7 @@ void CompareDialog::compare()
 
   for (int i=0; i < modelsList.size(); ++i) {
     multimodelprinter->setModel(i, &modelsList[i].model, &modelsList[i].gs);
-    QString name(modelsList.at(i).model.name);
+    QString name(modelsList.at(i).model.name.toQString());
     if (name.isEmpty())
       name = tr("Unnamed Model %1").arg(i+1);