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/cmd/importoff/main.go

@@ -21,6 +21,17 @@ type offRecord struct {
 	Code           string        `json:"code"`
 	ProductName    string        `json:"product_name"`
 	ProductNameEN  string        `json:"product_name_en"`
+	ProductNameRu  string        `json:"product_name_ru"`
+	ProductNameDe  string        `json:"product_name_de"`
+	ProductNameFr  string        `json:"product_name_fr"`
+	ProductNameEs  string        `json:"product_name_es"`
+	ProductNameIt  string        `json:"product_name_it"`
+	ProductNamePt  string        `json:"product_name_pt"`
+	ProductNameZh  string        `json:"product_name_zh"`
+	ProductNameJa  string        `json:"product_name_ja"`
+	ProductNameKo  string        `json:"product_name_ko"`
+	ProductNameAr  string        `json:"product_name_ar"`
+	ProductNameHi  string        `json:"product_name_hi"`
 	CategoriesTags []string      `json:"categories_tags"`
 	Nutriments     offNutriments `json:"nutriments"`
 	UniqueScansN   int           `json:"unique_scans_n"`
@@ -34,6 +45,12 @@ type offNutriments struct {
 	Fiber100g         *float64 `json:"fiber_100g"`
 }
 
+// aliasRow holds one multilingual alias for a product.
+type aliasRow struct {
+	lang  string
+	alias string
+}
+
 type productImportRow struct {
 	canonicalName string
 	barcode       string
@@ -43,6 +60,7 @@ type productImportRow struct {
 	fat           *float64
 	carbs         *float64
 	fiber         *float64
+	aliases       []aliasRow
 }
 
 // categoryPrefixes maps OpenFoodFacts category tag prefixes to our product_categories slugs.
@@ -217,6 +235,28 @@ func run() error {
 		}
 		seenInBatch[canonicalName] = true
 
+		// Collect non-English localised names as aliases so that searches in
+		// other languages (e.g. "сникерс" → "Snickers") can find the product.
+		langNames := map[string]string{
+			"ru": strings.TrimSpace(record.ProductNameRu),
+			"de": strings.TrimSpace(record.ProductNameDe),
+			"fr": strings.TrimSpace(record.ProductNameFr),
+			"es": strings.TrimSpace(record.ProductNameEs),
+			"it": strings.TrimSpace(record.ProductNameIt),
+			"pt": strings.TrimSpace(record.ProductNamePt),
+			"zh": strings.TrimSpace(record.ProductNameZh),
+			"ja": strings.TrimSpace(record.ProductNameJa),
+			"ko": strings.TrimSpace(record.ProductNameKo),
+			"ar": strings.TrimSpace(record.ProductNameAr),
+			"hi": strings.TrimSpace(record.ProductNameHi),
+		}
+		var productAliases []aliasRow
+		for lang, name := range langNames {
+			if name != "" && name != canonicalName {
+				productAliases = append(productAliases, aliasRow{lang: lang, alias: name})
+			}
+		}
+
 		totalAccepted++
 		productBatch = append(productBatch, productImportRow{
 			canonicalName: canonicalName,
@@ -227,6 +267,7 @@ func run() error {
 			fat:           record.Nutriments.Fat100g,
 			carbs:         record.Nutriments.Carbohydrates100g,
 			fiber:         record.Nutriments.Fiber100g,
+			aliases:       productAliases,
 		})
 
 		if len(productBatch) >= *batchSizeFlag {
@@ -336,18 +377,21 @@ func flushBatch(
 			carbs_per_100g    = COALESCE(EXCLUDED.carbs_per_100g,    products.carbs_per_100g),
 			fiber_per_100g    = COALESCE(EXCLUDED.fiber_per_100g,    products.fiber_per_100g),
 			updated_at        = now()
-		RETURNING id`)
+		RETURNING id, canonical_name`)
 	if upsertError != nil {
 		return 0, fmt.Errorf("upsert products: %w", upsertError)
 	}
 
+	// Build a canonical_name → product_id map so we can insert aliases below.
+	productIDByName := make(map[string]string, len(productBatch))
 	var insertedCount int64
 	for upsertRows.Next() {
-		var productID string
-		if scanError := upsertRows.Scan(&productID); scanError != nil {
+		var productID, canonicalName string
+		if scanError := upsertRows.Scan(&productID, &canonicalName); scanError != nil {
 			upsertRows.Close()
 			return 0, fmt.Errorf("scan upserted product id: %w", scanError)
 		}
+		productIDByName[canonicalName] = productID
 		insertedCount++
 	}
 	upsertRows.Close()
@@ -355,5 +399,35 @@ func flushBatch(
 		return 0, fmt.Errorf("iterate upsert results: %w", rowsError)
 	}
 
+	// Insert multilingual aliases collected during parsing.
+	// ON CONFLICT DO NOTHING so re-imports are safe.
+	aliasBatch := &pgx.Batch{}
+	for _, row := range productBatch {
+		productID, exists := productIDByName[row.canonicalName]
+		if !exists || len(row.aliases) == 0 {
+			continue
+		}
+		for _, aliasEntry := range row.aliases {
+			aliasBatch.Queue(
+				`INSERT INTO product_aliases (product_id, lang, alias)
+				 VALUES ($1, $2, $3)
+				 ON CONFLICT DO NOTHING`,
+				productID, aliasEntry.lang, aliasEntry.alias,
+			)
+		}
+	}
+	if aliasBatch.Len() > 0 {
+		batchResults := pgxConn.SendBatch(requestContext, aliasBatch)
+		for range aliasBatch.Len() {
+			if _, execError := batchResults.Exec(); execError != nil {
+				batchResults.Close()
+				return 0, fmt.Errorf("insert product alias: %w", execError)
+			}
+		}
+		if closeError := batchResults.Close(); closeError != nil {
+			return 0, fmt.Errorf("close alias batch: %w", closeError)
+		}
+	}
+
 	return insertedCount, nil
 }