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>

backend/internal/domain/diary/repository.go

@@ -124,6 +124,78 @@ func (r *Repository) Create(ctx context.Context, userID string, req CreateReques
 	return scanEntry(row)
 }
 
+// GetRecent returns the most recently logged distinct dishes and products for a user.
+func (r *Repository) GetRecent(ctx context.Context, userID string, limit int) ([]*RecentDiaryItem, error) {
+	if limit <= 0 || limit > 20 {
+		limit = 10
+	}
+	lang := locale.FromContext(ctx)
+
+	const q = `
+		WITH recent AS (
+			SELECT
+				dish_id, product_id,
+				MAX(created_at) AS last_used
+			FROM meal_diary
+			WHERE user_id = $1
+			GROUP BY dish_id, product_id
+			ORDER BY last_used DESC
+			LIMIT $2
+		)
+		SELECT
+			r.dish_id::text,
+			r.product_id::text,
+			COALESCE(dt.name, d.name, p.canonical_name)  AS name,
+			d.image_url,
+			COALESCE(pct.name, pc.name)                   AS category_name,
+			p.calories_per_100g,
+			(SELECT MIN(rec.calories_per_serving)
+			 FROM recipes rec WHERE rec.dish_id = r.dish_id) AS calories_per_serving
+		FROM recent r
+		LEFT JOIN dishes d
+			ON d.id = r.dish_id
+		LEFT JOIN dish_translations dt
+			ON dt.dish_id = d.id AND dt.lang = $3
+		LEFT JOIN products p
+			ON p.id = r.product_id
+		LEFT JOIN product_categories pc
+			ON pc.slug = p.category
+		LEFT JOIN product_category_translations pct
+			ON pct.product_category_slug = p.category AND pct.lang = $3
+		ORDER BY r.last_used DESC`
+
+	rows, queryError := r.pool.Query(ctx, q, userID, limit, lang)
+	if queryError != nil {
+		return nil, fmt.Errorf("get recent diary items: %w", queryError)
+	}
+	defer rows.Close()
+
+	var results []*RecentDiaryItem
+	for rows.Next() {
+		var item RecentDiaryItem
+		var dishID, productID *string
+		if scanError := rows.Scan(
+			&dishID, &productID,
+			&item.Name, &item.ImageURL, &item.CategoryName,
+			&item.CaloriesPer100g, &item.CaloriesPerServing,
+		); scanError != nil {
+			return nil, fmt.Errorf("scan recent diary item: %w", scanError)
+		}
+		item.DishID = dishID
+		item.ProductID = productID
+		if dishID != nil {
+			item.ItemType = "dish"
+		} else {
+			item.ItemType = "product"
+		}
+		results = append(results, &item)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return results, nil
+}
+
 // Delete removes a diary entry for the given user.
 func (r *Repository) Delete(ctx context.Context, id, userID string) error {
 	tag, deleteError := r.pool.Exec(ctx,