Use navigator context for close dialog

lib/app.dart

@@ -40,6 +40,7 @@ class _PeyaAppState extends ConsumerState<PeyaApp> with WindowListener {
   ProviderSubscription<WalletState>? _walletSubscription;
   final GlobalKey<ScaffoldMessengerState> _scaffoldMessengerKey =
       GlobalKey<ScaffoldMessengerState>();
+  final GlobalKey<NavigatorState> _navigatorKey = GlobalKey<NavigatorState>();
   String? _lastErrorMessage;
   bool _desktopCloseHookInitialized = false;
   bool _handlingWindowClose = false;
@@ -162,6 +163,8 @@ class _PeyaAppState extends ConsumerState<PeyaApp> with WindowListener {
       await windowManager.setPreventClose(false);
       await _logCloseDebug('handleNativeWindowClose destroying window');
       await windowManager.destroy();
+    } catch (error, stack) {
+      await _logCloseDebug('handleNativeWindowClose error: $error\n$stack');
     } finally {
       await _logCloseDebug('handleNativeWindowClose finished');
       _handlingWindowClose = false;
@@ -329,7 +332,8 @@ class _PeyaAppState extends ConsumerState<PeyaApp> with WindowListener {
         await _logCloseDebug('handleAppCloseRequest aborted: not mounted');
         return false;
       }
-      final dialogContext = _scaffoldMessengerKey.currentContext ?? context;
+      final dialogContext =
+          _navigatorKey.currentContext ?? _scaffoldMessengerKey.currentContext ?? context;
       final l10n = AppLocalizations.of(dialogContext);
       await _logCloseDebug('handleAppCloseRequest showing dialog');
       final decision = await showDialog<bool?>(
@@ -418,6 +422,7 @@ class _PeyaAppState extends ConsumerState<PeyaApp> with WindowListener {
       onGenerateTitle: (context) => AppLocalizations.of(context)!.appTitle,
       debugShowCheckedModeBanner: false,
       scaffoldMessengerKey: _scaffoldMessengerKey,
+      navigatorKey: _navigatorKey,
       theme: _buildTheme(),
       locale: config.resolveLocale(),
       supportedLocales: const [