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/l10n/app_localizations.dart

@@ -741,6 +741,54 @@ abstract class AppLocalizations {
   /// In en, this message translates to:
   /// **'per 100 g'**
   String get perHundredG;
+
+  /// No description provided for @searchFoodHint.
+  ///
+  /// In en, this message translates to:
+  /// **'Search products and dishes...'**
+  String get searchFoodHint;
+
+  /// No description provided for @recentlyUsedLabel.
+  ///
+  /// In en, this message translates to:
+  /// **'Recently used'**
+  String get recentlyUsedLabel;
+
+  /// No description provided for @productsSection.
+  ///
+  /// In en, this message translates to:
+  /// **'Products'**
+  String get productsSection;
+
+  /// No description provided for @dishesSection.
+  ///
+  /// In en, this message translates to:
+  /// **'Dishes'**
+  String get dishesSection;
+
+  /// No description provided for @noResultsForQuery.
+  ///
+  /// In en, this message translates to:
+  /// **'Nothing found for \"{query}\"'**
+  String noResultsForQuery(String query);
+
+  /// No description provided for @servingsLabel.
+  ///
+  /// In en, this message translates to:
+  /// **'Servings'**
+  String get servingsLabel;
+
+  /// No description provided for @addToDiary.
+  ///
+  /// In en, this message translates to:
+  /// **'Add to diary'**
+  String get addToDiary;
+
+  /// No description provided for @scanDishPhoto.
+  ///
+  /// In en, this message translates to:
+  /// **'Scan photo'**
+  String get scanDishPhoto;
 }
 
 class _AppLocalizationsDelegate