feat: translate recommendations and menu dishes into user language

- Generate recipes in English (reverted prompt to English-only)
- Add TranslateRecipes to OpenAI client (translate.go) — sends compact
  JSON payload of translatable fields, merges back into original recipes
- recommendation/handler.go: translate recipes in-memory before response
  when lang != "en"; falls back to English on error
- dish/repository.go: Create() now returns (dishID, recipeID, err) so
  callers can upsert dish_translations after saving
- menu/handler.go: saveRecipes returns savedRecipeEntry slice with dishID;
  saveDishTranslations calls TranslateRecipes then UpsertTranslation for
  each dish when the request locale is not English
- savedrecipe/repository.go: updated to ignore dishID from Create()
- init.go: wire openaiClient as RecipeTranslator and dishRepository as
  DishTranslator for menu.NewHandler

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

backend/cmd/server/init.go

@@ -38,7 +38,7 @@ func initApp(appConfig *config.Config, pool *pgxpool.Pool) (*App, error) {
 	mainPexelsAPIKey := newPexelsAPIKey(appConfig)
 	pexelsClient := newPexelsClient(mainPexelsAPIKey)
 	userProductRepository := userproduct.NewRepository(pool)
-	recommendationHandler := recommendation.NewHandler(openaiClient, pexelsClient, userRepository, userProductRepository)
+	recommendationHandler := recommendation.NewHandler(openaiClient, openaiClient, pexelsClient, userRepository, userProductRepository)
 	dishRepository := dish.NewRepository(pool)
 	savedrecipeRepository := savedrecipe.NewRepository(pool, dishRepository)
 	savedrecipeHandler := savedrecipe.NewHandler(savedrecipeRepository)
@@ -59,7 +59,7 @@ func initApp(appConfig *config.Config, pool *pgxpool.Pool) (*App, error) {
 	recognitionHandler := recognition.NewHandler(openaiClient, productRepository, jobRepository, kafkaProducer, sseBroker)
 
 	menuRepository := menu.NewRepository(pool)
-	menuHandler := menu.NewHandler(menuRepository, openaiClient, pexelsClient, userRepository, userProductRepository, dishRepository)
+	menuHandler := menu.NewHandler(menuRepository, openaiClient, openaiClient, dishRepository, pexelsClient, userRepository, userProductRepository, dishRepository)
 	diaryRepository := diary.NewRepository(pool)
 	diaryHandler := diary.NewHandler(diaryRepository, dishRepository, dishRepository)
 	homeHandler := home.NewHandler(pool)