feat: add pin lock / fix performance on history view

lib/views/bar_screen_view.dart

@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter/widget_previews.dart';
 import 'package:go_router/go_router.dart';
+import 'package:kooltab2/viewmodels/pin_lock_view_model.dart';
 import 'package:kooltab2/viewmodels/product_list_view_model.dart';
 import 'package:provider/provider.dart';
 import 'dart:io';
@@ -41,6 +42,14 @@ class BarScreenView extends StatelessWidget {
             onPressed: viewModel.load,
             icon: const Icon(Icons.refresh_rounded),
           ),
+          const SizedBox(width: 6),
+          IconButton(
+            tooltip: 'logout',
+            onPressed: (){
+              Provider.of<PinLockViewModel>(context, listen: false).lock();
+            },
+            icon: const Icon(Icons.logout)
+          ),
           const SizedBox(width: 8),
         ],
       ),