add quit button to contextual tab bar

app/lib/features/geckoview/features/browser/features/contextual_toolbar/domain/entities/toolbar_button_id.dart

@@ -42,4 +42,5 @@ enum ToolbarButtonId {
   pageDown,
   font,
   extensionShortcut,
+  quit,
 }

app/lib/features/geckoview/features/browser/features/contextual_toolbar/domain/entities/toolbar_button_spec.dart

@@ -158,6 +158,12 @@ const extensionShortcutToolbarButtonSpec = ToolbarButtonSpec(
   canBeFallbackTarget: false,
 );
 
+const quitToolbarButtonSpec = ToolbarButtonSpec(
+  id: ToolbarButtonId.quit,
+  defaultVisible: false,
+  canBeFallbackTarget: false,
+);
+
 const toolbarButtonSpecs = [
   backToolbarButtonSpec,
   forwardToolbarButtonSpec,
@@ -182,6 +188,7 @@ const toolbarButtonSpecs = [
   pageDownToolbarButtonSpec,
   fontToolbarButtonSpec,
   extensionShortcutToolbarButtonSpec,
+  quitToolbarButtonSpec,
 ];
 
 final Map<String, ToolbarButtonSpec> toolbarButtonSpecsById = {

app/lib/features/geckoview/features/browser/features/contextual_toolbar/presentation/toolbar_button_registry.dart

@@ -47,8 +47,10 @@ import 'package:weblibre/features/geckoview/features/readerview/presentation/con
 import 'package:weblibre/features/geckoview/features/tabs/data/entities/tab_mode.dart';
 import 'package:weblibre/features/settings/presentation/controllers/save_settings.dart';
 import 'package:weblibre/features/user/data/models/engine_settings.dart';
+import 'package:weblibre/features/user/domain/presentation/dialogs/quit_browser_dialog.dart';
 import 'package:weblibre/features/user/domain/repositories/engine_settings.dart';
 import 'package:weblibre/features/user/domain/repositories/general_settings.dart';
+import 'package:weblibre/utils/exit_app.dart';
 import 'package:weblibre/utils/move_to_background.dart';
 import 'package:weblibre/utils/ui_helper.dart' as ui_helper;
 
@@ -477,6 +479,30 @@ final List<ToolbarButtonDefinition> toolbarButtonRegistry = [
       return const _ExtensionShortcutToolbarButton();
     },
   ),
+  ToolbarButtonDefinition(
+    spec: quitToolbarButtonSpec,
+    label: 'Quit',
+    icon: MdiIcons.power,
+    longPressActions: ['Quit without confirmation'],
+    builder: (scope, context, ref) {
+      return IconButton(
+        onPressed: scope.isPreview
+            ? () {}
+            : () async {
+                final result = await showQuitBrowserDialog(context);
+                if (result == true) {
+                  await exitApp(ref.container);
+                }
+              },
+        onLongPress: scope.isPreview
+            ? null
+            : () async {
+                await exitApp(ref.container);
+              },
+        icon: const Icon(MdiIcons.power),
+      );
+    },
+  ),
 ];
 
 final Map<String, ToolbarButtonDefinition> toolbarButtonRegistryById = {