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_provider.dart

@@ -0,0 +1,27 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../../core/auth/auth_provider.dart';
+import '../../shared/models/product.dart';
+import 'food_search_service.dart';
+
+final foodSearchServiceProvider = Provider<FoodSearchService>(
+  (ref) => FoodSearchService(ref.read(apiClientProvider)),
+);
+
+/// Recently used diary items (dishes + products).
+final recentDiaryItemsProvider =
+    FutureProvider.autoDispose<List<RecentDiaryItem>>((ref) {
+  return ref.read(foodSearchServiceProvider).getRecent(limit: 15);
+});
+
+/// Product search results for the given query string.
+final productSearchProvider = FutureProvider.autoDispose
+    .family<List<CatalogProduct>, String>((ref, query) {
+  return ref.read(foodSearchServiceProvider).searchProducts(query);
+});
+
+/// Dish search results for the given query string.
+final dishSearchProvider = FutureProvider.autoDispose
+    .family<List<DishSearchResult>, String>((ref, query) {
+  return ref.read(foodSearchServiceProvider).searchDishes(query);
+});