fix permission error notification

apps/weblibre/lib/features/proxy/presentation/widgets/add_proxy_method_sheet.dart

@@ -21,7 +21,6 @@ import 'package:file_picker/file_picker.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:hooks_riverpod/hooks_riverpod.dart';
-import 'package:qr_code_scanner_plus/qr_code_scanner_plus.dart';
 import 'package:weblibre/core/branding/proxy_brands.dart';
 import 'package:weblibre/features/proxy/data/models/proxy_profile_seed.dart';
 import 'package:weblibre/features/proxy/domain/services/proxy_input_consumer.dart';
@@ -69,10 +68,7 @@ class AddProxyMethodSheet extends ConsumerWidget {
     }
 
     Future<void> scanQr() async {
-      final result = await showDialog<Barcode>(
-        context: context,
-        builder: (_) => const QrScannerDialog(),
-      );
+      final result = await showQrScannerDialog(context);
       final code = result?.code?.trim();
       if (code == null || code.isEmpty) return;
       if (!context.mounted) return;

apps/weblibre/lib/features/qr_scanner/presentation/dialogs/qr_scanner_dialog.dart

@@ -21,9 +21,26 @@ import 'dart:async';
 
 import 'package:flutter/material.dart';
 import 'package:flutter_hooks/flutter_hooks.dart';
+import 'package:permission_handler/permission_handler.dart';
 import 'package:qr_code_scanner_plus/qr_code_scanner_plus.dart';
 import 'package:weblibre/utils/ui_helper.dart' as ui_helper;
 
+Future<Barcode?> showQrScannerDialog(BuildContext context) async {
+  final cameraPermission = await Permission.camera.request();
+
+  if (!context.mounted) return null;
+
+  if (!cameraPermission.isGranted) {
+    ui_helper.showErrorMessage(context, 'No Camera Permission granted');
+    return null;
+  }
+
+  return showDialog<Barcode>(
+    context: context,
+    builder: (_) => const QrScannerDialog(),
+  );
+}
+
 class QrScannerDialog extends HookWidget {
   const QrScannerDialog({super.key});
 
@@ -33,6 +50,7 @@ class QrScannerDialog extends HookWidget {
     final qrController = useState<QRViewController?>(null);
 
     final flashState = useState(false);
+    final permissionDeniedHandled = useRef(false);
 
     useEffect(() {
       StreamSubscription<Barcode>? sub;
@@ -83,11 +101,13 @@ class QrScannerDialog extends HookWidget {
               qrController.value = controller;
             },
             onPermissionSet: (controller, result) {
-              if (!result) {
+              if (!result && !permissionDeniedHandled.value) {
+                permissionDeniedHandled.value = true;
                 ui_helper.showErrorMessage(
                   context,
                   'No Camera Permission granted',
                 );
+                Navigator.of(context).pop();
               }
             },
           ),

apps/weblibre/lib/features/sync/presentation/screens/sync_settings.dart

@@ -24,7 +24,6 @@ import 'package:flutter/services.dart';
 import 'package:flutter_hooks/flutter_hooks.dart';
 import 'package:flutter_mozilla_components/flutter_mozilla_components.dart';
 import 'package:hooks_riverpod/hooks_riverpod.dart';
-import 'package:qr_code_scanner_plus/qr_code_scanner_plus.dart';
 import 'package:weblibre/core/logger.dart';
 import 'package:weblibre/core/providers/format.dart';
 import 'package:weblibre/features/qr_scanner/presentation/dialogs/qr_scanner_dialog.dart';
@@ -146,10 +145,7 @@ class SyncSettingsScreen extends HookConsumerWidget {
                     ),
                     trailing: const Icon(Icons.chevron_right),
                     onTap: () async {
-                      final barcode = await showDialog<Barcode>(
-                        context: context,
-                        builder: (_) => const QrScannerDialog(),
-                      );
+                      final barcode = await showQrScannerDialog(context);
 
                       final code = barcode?.code;
                       if (code == null || code.isEmpty) return;

apps/weblibre/lib/presentation/widgets/qr_scanner_button.dart

@@ -32,12 +32,7 @@ class QrScannerButton extends HookConsumerWidget {
   Widget build(BuildContext context, WidgetRef ref) {
     return IconButton(
       onPressed: () async {
-        final result = await showDialog<Barcode>(
-          context: context,
-          builder: (context) {
-            return const QrScannerDialog();
-          },
-        );
+        final result = await showQrScannerDialog(context);
 
         onScanResult(result);
       },