fix: alot

lib/viewmodels/bar_screen_view_model.dart

@@ -37,6 +37,15 @@ class BarScreenViewModel extends ChangeNotifier {
   BarTab? get selectedTab =>
       _tabs.firstWhereOrNull((tab) => tab.id == _selectedTabId);
 
+  bool hasOpenTabNamed(String name, {String? exceptTabId}) {
+    final normalized = name.trim().toLowerCase();
+    return _tabs.any(
+      (tab) =>
+          tab.id != exceptTabId &&
+          tab.customerName.trim().toLowerCase() == normalized,
+    );
+  }
+
   void ensureLoaded() {
     if (_subscription != null) return;