feat: show dish recognition result as bottom sheet on home screen

Remove "Определить блюдо" from ScanScreen and the /scan/dish route.
The + button on each meal card now triggers dish recognition inline —
picks image, shows loading dialog, then presents DishResultSheet as a
modal bottom sheet. After adding to diary the sheet closes and the user
stays on home.

Also fix Navigator.pop crash: showDialog uses the root navigator by
default, so capture Navigator.of(context, rootNavigator: true) before
the async gap and use it to close the loading dialog.

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

client/lib/features/scan/scan_screen.dart

@@ -3,17 +3,9 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:go_router/go_router.dart';
 import 'package:image_picker/image_picker.dart';
 
-import '../../core/auth/auth_provider.dart';
 import 'recognition_service.dart';
 
-// Provider wired to the shared ApiClient.
-final _recognitionServiceProvider = Provider<RecognitionService>((ref) {
-  return RecognitionService(ref.read(apiClientProvider));
-});
-
 /// Entry screen — lets the user choose how to add products.
-/// If [GoRouterState.extra] is a non-null String, it is treated as a meal type ID
-/// and the screen immediately opens the camera for dish recognition.
 class ScanScreen extends ConsumerStatefulWidget {
   const ScanScreen({super.key});
 
@@ -22,24 +14,6 @@ class ScanScreen extends ConsumerStatefulWidget {
 }
 
 class _ScanScreenState extends ConsumerState<ScanScreen> {
-  bool _autoStarted = false;
-
-  @override
-  void didChangeDependencies() {
-    super.didChangeDependencies();
-    if (_autoStarted) return;
-    final mealType = GoRouterState.of(context).extra as String?;
-    if (mealType != null && mealType.isNotEmpty) {
-      _autoStarted = true;
-      // Defer to avoid calling context navigation during build.
-      WidgetsBinding.instance.addPostFrameCallback((_) {
-        if (mounted) {
-          _pickAndRecognize(context, _Mode.dish, mealType: mealType);
-        }
-      });
-    }
-  }
-
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -68,13 +42,6 @@ class _ScanScreenState extends ConsumerState<ScanScreen> {
             onTap: () => _pickAndRecognize(context, _Mode.products),
           ),
           const SizedBox(height: 16),
-          _ModeCard(
-            emoji: '🍽️',
-            title: 'Определить блюдо',
-            subtitle: 'КБЖУ≈ по фото готового блюда',
-            onTap: () => _pickAndRecognize(context, _Mode.dish),
-          ),
-          const SizedBox(height: 16),
           _ModeCard(
             emoji: '✏️',
             title: 'Добавить вручную',
@@ -88,9 +55,8 @@ class _ScanScreenState extends ConsumerState<ScanScreen> {
 
   Future<void> _pickAndRecognize(
     BuildContext context,
-    _Mode mode, {
-    String? mealType,
-  }) async {
+    _Mode mode,
+  ) async {
     final picker = ImagePicker();
 
     List<XFile> files = [];
@@ -118,7 +84,7 @@ class _ScanScreenState extends ConsumerState<ScanScreen> {
     }
 
     if (!context.mounted) return;
-    final service = ref.read(_recognitionServiceProvider);
+    final service = ref.read(recognitionServiceProvider);
 
     // Show loading overlay while the AI processes.
     showDialog(
@@ -141,12 +107,6 @@ class _ScanScreenState extends ConsumerState<ScanScreen> {
             Navigator.pop(context);
             context.push('/scan/confirm', extra: items);
           }
-        case _Mode.dish:
-          final dish = await service.recognizeDish(files.first);
-          if (context.mounted) {
-            Navigator.pop(context);
-            context.push('/scan/dish', extra: {'dish': dish, 'meal_type': mealType});
-          }
       }
     } catch (recognitionError) {
       debugPrint('Recognition error: $recognitionError');
@@ -189,7 +149,7 @@ class _ScanScreenState extends ConsumerState<ScanScreen> {
 // Mode enum
 // ---------------------------------------------------------------------------
 
-enum _Mode { receipt, products, dish }
+enum _Mode { receipt, products }
 
 // ---------------------------------------------------------------------------
 // Widgets