feat: food search sheet with FTS+trgm, dish/recent endpoints, multilingual aliases

Backend:
- GET /dishes/search — hybrid FTS (english + simple) + trgm + ILIKE search
- GET /diary/recent — recently used dishes and products for the current user
- product search upgraded: FTS on canonical_name and product_aliases, ranked by GREATEST(ts_rank, similarity)
- importoff: collect product_name_ru/de/fr/... as product_aliases for multilingual search (e.g. "сникерс" → "Snickers")
- migrations: FTS + trgm indexes merged into 001_initial_schema.sql (002 removed)

Flutter:
- FoodSearchSheet: debounced search field, recently-used section, product/dish results, scan-photo and barcode chips
- DishPortionSheet: quick ½/1/1½/2 buttons + custom input
- + button in meal card now opens FoodSearchSheet instead of going directly to AI scan
- 7 new l10n keys across all 12 languages

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

client/lib/features/diary/food_search_service.dart

@@ -0,0 +1,108 @@
+import '../../core/api/api_client.dart';
+import '../../shared/models/product.dart';
+
+/// Lightweight dish result returned by GET /dishes/search.
+class DishSearchResult {
+  final String id;
+  final String name;
+  final String? imageUrl;
+  final double avgRating;
+
+  const DishSearchResult({
+    required this.id,
+    required this.name,
+    this.imageUrl,
+    required this.avgRating,
+  });
+
+  factory DishSearchResult.fromJson(Map<String, dynamic> json) {
+    return DishSearchResult(
+      id: json['id'] as String,
+      name: json['name'] as String,
+      imageUrl: json['image_url'] as String?,
+      avgRating: (json['avg_rating'] as num?)?.toDouble() ?? 0,
+    );
+  }
+}
+
+/// One item from GET /diary/recent.
+class RecentDiaryItem {
+  final String itemType; // "dish" | "product"
+  final String? dishId;
+  final String? productId;
+  final String name;
+  final String? imageUrl;
+  final String? categoryName;
+  final double? caloriesPer100g;
+  final double? caloriesPerServing;
+
+  const RecentDiaryItem({
+    required this.itemType,
+    this.dishId,
+    this.productId,
+    required this.name,
+    this.imageUrl,
+    this.categoryName,
+    this.caloriesPer100g,
+    this.caloriesPerServing,
+  });
+
+  factory RecentDiaryItem.fromJson(Map<String, dynamic> json) {
+    return RecentDiaryItem(
+      itemType: json['item_type'] as String? ?? 'dish',
+      dishId: json['dish_id'] as String?,
+      productId: json['product_id'] as String?,
+      name: json['name'] as String? ?? '',
+      imageUrl: json['image_url'] as String?,
+      categoryName: json['category_name'] as String?,
+      caloriesPer100g: (json['calories_per_100g'] as num?)?.toDouble(),
+      caloriesPerServing: (json['calories_per_serving'] as num?)?.toDouble(),
+    );
+  }
+
+  /// For products: calories per 100 g; for dishes: calories per serving.
+  double? get displayCalories =>
+      itemType == 'product' ? caloriesPer100g : caloriesPerServing;
+}
+
+/// Service for searching products/dishes and loading recently used diary items.
+class FoodSearchService {
+  const FoodSearchService(this._client);
+
+  final ApiClient _client;
+
+  /// Searches catalog products by name.
+  Future<List<CatalogProduct>> searchProducts(String query) async {
+    if (query.isEmpty) return [];
+    final list = await _client.getList(
+      '/products/search',
+      params: {'q': query, 'limit': '20'},
+    );
+    return list
+        .map((item) => CatalogProduct.fromJson(item as Map<String, dynamic>))
+        .toList();
+  }
+
+  /// Searches dishes by name.
+  Future<List<DishSearchResult>> searchDishes(String query) async {
+    if (query.isEmpty) return [];
+    final list = await _client.getList(
+      '/dishes/search',
+      params: {'q': query, 'limit': '10'},
+    );
+    return list
+        .map((item) => DishSearchResult.fromJson(item as Map<String, dynamic>))
+        .toList();
+  }
+
+  /// Returns recent diary items (dishes and products) for the current user.
+  Future<List<RecentDiaryItem>> getRecent({int limit = 10}) async {
+    final list = await _client.getList(
+      '/diary/recent',
+      params: {'limit': '$limit'},
+    );
+    return list
+        .map((item) => RecentDiaryItem.fromJson(item as Map<String, dynamic>))
+        .toList();
+  }
+}