feat: localise scan screen (12 languages)

Replace all hardcoded Russian strings in ScanScreen and _LoadingDialog
with AppLocalizations keys; add addFromReceiptOrPhoto, chooseMethod,
photoReceipt, photoReceiptSubtitle, photoProducts, photoProductsSubtitle,
recognizing keys to all 12 ARB files and regenerate AppLocalizations.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/lib/features/scan/scan_screen.dart

@@ -3,6 +3,7 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:go_router/go_router.dart';
 import 'package:image_picker/image_picker.dart';
 
+import '../../l10n/app_localizations.dart';
 import 'recognition_service.dart';
 
 /// Entry screen — lets the user choose how to add products.
@@ -16,38 +17,32 @@ class ScanScreen extends ConsumerStatefulWidget {
 class _ScanScreenState extends ConsumerState<ScanScreen> {
   @override
   Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context)!;
     return Scaffold(
-      appBar: AppBar(title: const Text('Добавить продукты')),
+      appBar: AppBar(title: Text(l10n.addFromReceiptOrPhoto)),
       body: ListView(
         padding: const EdgeInsets.all(20),
         children: [
           const SizedBox(height: 16),
           Text(
-            'Выберите способ',
+            l10n.chooseMethod,
             style: Theme.of(context).textTheme.titleLarge,
             textAlign: TextAlign.center,
           ),
           const SizedBox(height: 32),
           _ModeCard(
             emoji: '🧾',
-            title: 'Сфотографировать чек',
-            subtitle: 'Распознаем все продукты из чека',
+            title: l10n.photoReceipt,
+            subtitle: l10n.photoReceiptSubtitle,
             onTap: () => _pickAndRecognize(context, _Mode.receipt),
           ),
           const SizedBox(height: 16),
           _ModeCard(
             emoji: '🥦',
-            title: 'Сфотографировать продукты',
-            subtitle: 'Холодильник, стол, полка — до 3 фото',
+            title: l10n.photoProducts,
+            subtitle: l10n.photoProductsSubtitle,
             onTap: () => _pickAndRecognize(context, _Mode.products),
           ),
-          const SizedBox(height: 16),
-          _ModeCard(
-            emoji: '✏️',
-            title: 'Добавить вручную',
-            subtitle: 'Ввести название, количество и срок',
-            onTap: () => context.push('/products/add'),
-          ),
         ],
       ),
     );
@@ -85,12 +80,13 @@ class _ScanScreenState extends ConsumerState<ScanScreen> {
 
     if (!context.mounted) return;
     final service = ref.read(recognitionServiceProvider);
+    final l10n = AppLocalizations.of(context)!;
 
     // Show loading overlay while the AI processes.
     showDialog(
       context: context,
       barrierDismissible: false,
-      builder: (_) => const _LoadingDialog(),
+      builder: (dialogContext) => _LoadingDialog(label: l10n.recognizing),
     );
 
     try {
@@ -113,15 +109,14 @@ class _ScanScreenState extends ConsumerState<ScanScreen> {
       if (context.mounted) {
         Navigator.pop(context); // close loading
         ScaffoldMessenger.of(context).showSnackBar(
-          const SnackBar(
-            content: Text('Не удалось распознать. Попробуйте ещё раз.'),
-          ),
+          SnackBar(content: Text(l10n.recognitionFailed)),
         );
       }
     }
   }
 
   Future<ImageSource?> _chooseSource(BuildContext context) async {
+    final l10n = AppLocalizations.of(context)!;
     return showModalBottomSheet<ImageSource>(
       context: context,
       builder: (_) => SafeArea(
@@ -130,12 +125,12 @@ class _ScanScreenState extends ConsumerState<ScanScreen> {
           children: [
             ListTile(
               leading: const Icon(Icons.camera_alt),
-              title: const Text('Камера'),
+              title: Text(l10n.camera),
               onTap: () => Navigator.pop(context, ImageSource.camera),
             ),
             ListTile(
               leading: const Icon(Icons.photo_library),
-              title: const Text('Галерея'),
+              title: Text(l10n.gallery),
               onTap: () => Navigator.pop(context, ImageSource.gallery),
             ),
           ],
@@ -186,17 +181,19 @@ class _ModeCard extends StatelessWidget {
 }
 
 class _LoadingDialog extends StatelessWidget {
-  const _LoadingDialog();
+  const _LoadingDialog({required this.label});
+
+  final String label;
 
   @override
   Widget build(BuildContext context) {
-    return const AlertDialog(
+    return AlertDialog(
       content: Column(
         mainAxisSize: MainAxisSize.min,
         children: [
-          CircularProgressIndicator(),
-          SizedBox(height: 16),
-          Text('Распознаём...'),
+          const CircularProgressIndicator(),
+          const SizedBox(height: 16),
+          Text(label),
         ],
       ),
     );