feat: rename ingredients→products, products→user_products; add barcode/OFF import

- Rename catalog: ingredient/* → product/* (canonical_name, barcode, nutrition per 100g)
- Rename pantry: product/* → userproduct/* (user-owned items with expiry)
- Squash migrations into single 001_initial_schema.sql (clean-db baseline)
- product_categories: add English canonical name column; fix COALESCE in queries
- Remove product_translations: product names are stored in their original language
- Add default_unit_name to product API responses via unit_translations JOIN
- Add cmd/importoff: bulk import from OpenFoodFacts JSONL dump (COPY + ON CONFLICT)
- Diary: support product_id entries alongside dish_id (CHECK num_nonnulls = 1)
- Home: getLoggedCalories joins both recipes and catalog products
- Flutter: rename models/providers/services to match backend rename
- Flutter: add barcode scan flow for diary (mobile_scanner, product_portion_sheet)
- Flutter: localise 6 new keys across 12 languages (barcode scan, portion weight)
- Routes: GET /products/search, GET /products/barcode/{barcode}, /user-products

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

backend/internal/infra/server/server.go

@@ -8,16 +8,16 @@ import (
 	"github.com/food-ai/backend/internal/domain/diary"
 	"github.com/food-ai/backend/internal/domain/dish"
 	"github.com/food-ai/backend/internal/domain/home"
-	"github.com/food-ai/backend/internal/domain/ingredient"
 	"github.com/food-ai/backend/internal/domain/language"
 	"github.com/food-ai/backend/internal/domain/menu"
 	"github.com/food-ai/backend/internal/infra/middleware"
-	"github.com/food-ai/backend/internal/domain/recipe"
 	"github.com/food-ai/backend/internal/domain/product"
+	"github.com/food-ai/backend/internal/domain/recipe"
 	"github.com/food-ai/backend/internal/domain/recognition"
 	"github.com/food-ai/backend/internal/domain/recommendation"
 	"github.com/food-ai/backend/internal/domain/savedrecipe"
 	"github.com/food-ai/backend/internal/domain/user"
+	"github.com/food-ai/backend/internal/domain/userproduct"
 	"github.com/go-chi/chi/v5"
 	"github.com/jackc/pgx/v5/pgxpool"
 )
@@ -28,8 +28,8 @@ func NewRouter(
 	userHandler *user.Handler,
 	recommendationHandler *recommendation.Handler,
 	savedRecipeHandler *savedrecipe.Handler,
-	ingredientHandler *ingredient.Handler,
 	productHandler *product.Handler,
+	userProductHandler *userproduct.Handler,
 	recognitionHandler *recognition.Handler,
 	menuHandler *menu.Handler,
 	diaryHandler *diary.Handler,
@@ -67,7 +67,8 @@ func NewRouter(
 	r.Group(func(r chi.Router) {
 		r.Use(authMiddleware)
 
-		r.Get("/ingredients/search", ingredientHandler.Search)
+		r.Get("/products/search", productHandler.Search)
+		r.Get("/products/barcode/{barcode}", productHandler.GetByBarcode)
 
 		r.Get("/profile", userHandler.Get)
 		r.Put("/profile", userHandler.Update)
@@ -81,12 +82,12 @@ func NewRouter(
 			r.Delete("/{id}", savedRecipeHandler.Delete)
 		})
 
-		r.Route("/products", func(r chi.Router) {
-			r.Get("/", productHandler.List)
-			r.Post("/", productHandler.Create)
-			r.Post("/batch", productHandler.BatchCreate)
-			r.Put("/{id}", productHandler.Update)
-			r.Delete("/{id}", productHandler.Delete)
+		r.Route("/user-products", func(r chi.Router) {
+			r.Get("/", userProductHandler.List)
+			r.Post("/", userProductHandler.Create)
+			r.Post("/batch", userProductHandler.BatchCreate)
+			r.Put("/{id}", userProductHandler.Update)
+			r.Delete("/{id}", userProductHandler.Delete)
 		})
 
 		r.Route("/dishes", func(r chi.Router) {