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/tests/userproduct/handler_test.go

@@ -0,0 +1,200 @@
+package userproduct_test
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	"github.com/food-ai/backend/internal/domain/userproduct"
+	userproductmocks "github.com/food-ai/backend/internal/domain/userproduct/mocks"
+	"github.com/food-ai/backend/internal/infra/middleware"
+	"github.com/go-chi/chi/v5"
+)
+
+type alwaysAuthValidator struct{ userID string }
+
+func (v *alwaysAuthValidator) ValidateAccessToken(_ string) (*middleware.TokenClaims, error) {
+	return &middleware.TokenClaims{UserID: v.userID}, nil
+}
+
+func buildRouter(handler *userproduct.Handler, userID string) *chi.Mux {
+	router := chi.NewRouter()
+	router.Use(middleware.Auth(&alwaysAuthValidator{userID: userID}))
+	router.Get("/user-products", handler.List)
+	router.Post("/user-products", handler.Create)
+	router.Post("/user-products/batch", handler.BatchCreate)
+	router.Put("/user-products/{id}", handler.Update)
+	router.Delete("/user-products/{id}", handler.Delete)
+	return router
+}
+
+func authorizedRequest(method, target string, body []byte) *http.Request {
+	request := httptest.NewRequest(method, target, bytes.NewReader(body))
+	request.Header.Set("Authorization", "Bearer test-token")
+	request.Header.Set("Content-Type", "application/json")
+	return request
+}
+
+func makeUserProduct(name string) *userproduct.UserProduct {
+	return &userproduct.UserProduct{
+		ID:          "prod-1",
+		UserID:      "user-1",
+		Name:        name,
+		Quantity:    1,
+		Unit:        "pcs",
+		StorageDays: 7,
+		AddedAt:     time.Now(),
+		ExpiresAt:   time.Now().AddDate(0, 0, 7),
+		DaysLeft:    7,
+	}
+}
+
+func TestList_Success(t *testing.T) {
+	mockRepo := &userproductmocks.MockUserProductRepository{
+		ListFn: func(ctx context.Context, userID string) ([]*userproduct.UserProduct, error) {
+			return []*userproduct.UserProduct{makeUserProduct("Milk")}, nil
+		},
+	}
+	handler := userproduct.NewHandler(mockRepo)
+	router := buildRouter(handler, "user-1")
+
+	recorder := httptest.NewRecorder()
+	router.ServeHTTP(recorder, authorizedRequest(http.MethodGet, "/user-products", nil))
+
+	if recorder.Code != http.StatusOK {
+		t.Errorf("expected 200, got %d", recorder.Code)
+	}
+}
+
+func TestCreate_MissingName(t *testing.T) {
+	handler := userproduct.NewHandler(&userproductmocks.MockUserProductRepository{})
+	router := buildRouter(handler, "user-1")
+
+	body, _ := json.Marshal(map[string]any{"quantity": 1})
+	recorder := httptest.NewRecorder()
+	router.ServeHTTP(recorder, authorizedRequest(http.MethodPost, "/user-products", body))
+
+	if recorder.Code != http.StatusBadRequest {
+		t.Errorf("expected 400, got %d", recorder.Code)
+	}
+}
+
+func TestCreate_Success(t *testing.T) {
+	mockRepo := &userproductmocks.MockUserProductRepository{
+		CreateFn: func(ctx context.Context, userID string, req userproduct.CreateRequest) (*userproduct.UserProduct, error) {
+			return makeUserProduct(req.Name), nil
+		},
+	}
+	handler := userproduct.NewHandler(mockRepo)
+	router := buildRouter(handler, "user-1")
+
+	body, _ := json.Marshal(userproduct.CreateRequest{Name: "Milk", Quantity: 1, Unit: "L"})
+	recorder := httptest.NewRecorder()
+	router.ServeHTTP(recorder, authorizedRequest(http.MethodPost, "/user-products", body))
+
+	if recorder.Code != http.StatusCreated {
+		t.Errorf("expected 201, got %d", recorder.Code)
+	}
+}
+
+func TestBatchCreate_Success(t *testing.T) {
+	mockRepo := &userproductmocks.MockUserProductRepository{
+		BatchCreateFn: func(ctx context.Context, userID string, items []userproduct.CreateRequest) ([]*userproduct.UserProduct, error) {
+			result := make([]*userproduct.UserProduct, len(items))
+			for index, item := range items {
+				result[index] = makeUserProduct(item.Name)
+			}
+			return result, nil
+		},
+	}
+	handler := userproduct.NewHandler(mockRepo)
+	router := buildRouter(handler, "user-1")
+
+	body, _ := json.Marshal([]userproduct.CreateRequest{
+		{Name: "Milk", Quantity: 1, Unit: "L"},
+		{Name: "Eggs", Quantity: 12, Unit: "pcs"},
+	})
+	recorder := httptest.NewRecorder()
+	router.ServeHTTP(recorder, authorizedRequest(http.MethodPost, "/user-products/batch", body))
+
+	if recorder.Code != http.StatusCreated {
+		t.Errorf("expected 201, got %d", recorder.Code)
+	}
+}
+
+func TestUpdate_NotFound(t *testing.T) {
+	mockRepo := &userproductmocks.MockUserProductRepository{
+		UpdateFn: func(ctx context.Context, id, userID string, req userproduct.UpdateRequest) (*userproduct.UserProduct, error) {
+			return nil, userproduct.ErrNotFound
+		},
+	}
+	handler := userproduct.NewHandler(mockRepo)
+	router := buildRouter(handler, "user-1")
+
+	namePtr := "NewName"
+	body, _ := json.Marshal(userproduct.UpdateRequest{Name: &namePtr})
+	recorder := httptest.NewRecorder()
+	router.ServeHTTP(recorder, authorizedRequest(http.MethodPut, "/user-products/nonexistent", body))
+
+	if recorder.Code != http.StatusNotFound {
+		t.Errorf("expected 404, got %d", recorder.Code)
+	}
+}
+
+func TestUpdate_Success(t *testing.T) {
+	mockRepo := &userproductmocks.MockUserProductRepository{
+		UpdateFn: func(ctx context.Context, id, userID string, req userproduct.UpdateRequest) (*userproduct.UserProduct, error) {
+			updated := makeUserProduct(*req.Name)
+			return updated, nil
+		},
+	}
+	handler := userproduct.NewHandler(mockRepo)
+	router := buildRouter(handler, "user-1")
+
+	namePtr := "Oat Milk"
+	body, _ := json.Marshal(userproduct.UpdateRequest{Name: &namePtr})
+	recorder := httptest.NewRecorder()
+	router.ServeHTTP(recorder, authorizedRequest(http.MethodPut, "/user-products/prod-1", body))
+
+	if recorder.Code != http.StatusOK {
+		t.Errorf("expected 200, got %d", recorder.Code)
+	}
+}
+
+func TestDelete_NotFound(t *testing.T) {
+	mockRepo := &userproductmocks.MockUserProductRepository{
+		DeleteFn: func(ctx context.Context, id, userID string) error {
+			return userproduct.ErrNotFound
+		},
+	}
+	handler := userproduct.NewHandler(mockRepo)
+	router := buildRouter(handler, "user-1")
+
+	recorder := httptest.NewRecorder()
+	router.ServeHTTP(recorder, authorizedRequest(http.MethodDelete, "/user-products/nonexistent", nil))
+
+	if recorder.Code != http.StatusNotFound {
+		t.Errorf("expected 404, got %d", recorder.Code)
+	}
+}
+
+func TestDelete_Success(t *testing.T) {
+	mockRepo := &userproductmocks.MockUserProductRepository{
+		DeleteFn: func(ctx context.Context, id, userID string) error {
+			return nil
+		},
+	}
+	handler := userproduct.NewHandler(mockRepo)
+	router := buildRouter(handler, "user-1")
+
+	recorder := httptest.NewRecorder()
+	router.ServeHTTP(recorder, authorizedRequest(http.MethodDelete, "/user-products/prod-1", nil))
+
+	if recorder.Code != http.StatusNoContent {
+		t.Errorf("expected 204, got %d", recorder.Code)
+	}
+}