feat: core schema redesign — dishes, structured recipes, cuisines, tags (iteration 7)

Replaces the flat JSONB-based recipe schema with a normalized relational model:

Schema (migrations consolidated to 001_initial_schema + 002_seed_data):
- New: dishes, dish_translations, dish_tags — canonical dish catalog
- New: cuisines, tags, dish_categories with _translations tables + full seed data
- New: recipe_ingredients, recipe_steps with _translations (replaces JSONB blobs)
- New: user_saved_recipes thin bookmark (drops saved_recipes + saved_recipe_translations)
- New: product_ingredients M2M table
- recipes: now a cooking variant of a dish (dish_id FK, no title/JSONB columns)
- recipe_translations: repurposed to per-language notes only
- products: mapping_id → primary_ingredient_id
- menu_items: recipe_id FK → recipes; adds dish_id
- meal_diary: adds dish_id, recipe_id → recipes, portion_g

Backend (Go):
- New packages: internal/cuisine, internal/tag, internal/dish (registry + handler + repo)
- New GET /cuisines, GET /tags (public), GET /dishes, GET /dishes/{id}, GET /recipes/{id}
- recipe, savedrecipe, menu, diary, product, ingredient packages updated for new schema

Flutter:
- New models: Cuisine, Tag; new providers: cuisineNamesProvider, tagNamesProvider
- recipe.dart: RecipeIngredient gains unit_code + effectiveUnit getter
- saved_recipe.dart: thin model, manual fromJson, computed nutrition getter
- diary_entry.dart: adds dishId, recipeId, portionG
- recipe_detail_screen.dart: localized cuisine/tag names via providers

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

backend/internal/menu/repository.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/food-ai/backend/internal/locale"
 	"github.com/jackc/pgx/v5"
 	"github.com/jackc/pgx/v5/pgxpool"
 )
@@ -27,18 +28,28 @@ func NewRepository(pool *pgxpool.Pool) *Repository {
 // GetByWeek loads the full menu plan for the user and given Monday date (YYYY-MM-DD).
 // Returns nil, nil when no plan exists for that week.
 func (r *Repository) GetByWeek(ctx context.Context, userID, weekStart string) (*MenuPlan, error) {
+	lang := locale.FromContext(ctx)
+
 	const q = `
 		SELECT mp.id, mp.week_start::text,
 		       mi.id, mi.day_of_week, mi.meal_type,
-		       sr.id, sr.title, COALESCE(sr.image_url, ''), sr.nutrition
+		       rec.id,
+		       COALESCE(dt.name, d.name),
+		       COALESCE(d.image_url, ''),
+		       rec.calories_per_serving,
+		       rec.protein_per_serving,
+		       rec.fat_per_serving,
+		       rec.carbs_per_serving
 		FROM menu_plans mp
 		LEFT JOIN menu_items mi ON mi.menu_plan_id = mp.id
-		LEFT JOIN saved_recipes sr ON sr.id = mi.recipe_id
+		LEFT JOIN recipes rec ON rec.id = mi.recipe_id
+		LEFT JOIN dishes d ON d.id = rec.dish_id
+		LEFT JOIN dish_translations dt ON dt.dish_id = d.id AND dt.lang = $3
 		WHERE mp.user_id = $1 AND mp.week_start::text = $2
 		ORDER BY mi.day_of_week,
 		         CASE mi.meal_type WHEN 'breakfast' THEN 1 WHEN 'lunch' THEN 2 ELSE 3 END`
 
-	rows, err := r.pool.Query(ctx, q, userID, weekStart)
+	rows, err := r.pool.Query(ctx, q, userID, weekStart, lang)
 	if err != nil {
 		return nil, fmt.Errorf("get menu by week: %w", err)
 	}
@@ -49,16 +60,17 @@ func (r *Repository) GetByWeek(ctx context.Context, userID, weekStart string) (*
 
 	for rows.Next() {
 		var (
-			planID, planWeekStart         string
-			itemID, mealType              *string
-			dow                           *int
-			recipeID, title, imageURL     *string
-			nutritionRaw                  []byte
+			planID, planWeekStart          string
+			itemID, mealType               *string
+			dow                            *int
+			recipeID, title, imageURL      *string
+			calPer, protPer, fatPer, carbPer *float64
 		)
 		if err := rows.Scan(
 			&planID, &planWeekStart,
 			&itemID, &dow, &mealType,
-			&recipeID, &title, &imageURL, &nutritionRaw,
+			&recipeID, &title, &imageURL,
+			&calPer, &protPer, &fatPer, &carbPer,
 		); err != nil {
 			return nil, fmt.Errorf("scan menu row: %w", err)
 		}
@@ -79,9 +91,11 @@ func (r *Repository) GetByWeek(ctx context.Context, userID, weekStart string) (*
 
 		slot := MealSlot{ID: *itemID, MealType: *mealType}
 		if recipeID != nil && title != nil {
-			var nutrition NutritionInfo
-			if len(nutritionRaw) > 0 {
-				_ = json.Unmarshal(nutritionRaw, &nutrition)
+			nutrition := NutritionInfo{
+				Calories: derefFloat(calPer),
+				ProteinG: derefFloat(protPer),
+				FatG:     derefFloat(fatPer),
+				CarbsG:   derefFloat(carbPer),
 			}
 			slot.Recipe = &MenuRecipe{
 				ID:        *recipeID,
@@ -257,10 +271,12 @@ func (r *Repository) GetPlanIDByWeek(ctx context.Context, userID, weekStart stri
 // GetIngredientsByPlan returns all ingredients from all recipes in the plan.
 func (r *Repository) GetIngredientsByPlan(ctx context.Context, planID string) ([]ingredientRow, error) {
 	rows, err := r.pool.Query(ctx, `
-		SELECT sr.ingredients, sr.nutrition, mi.meal_type
+		SELECT ri.name, ri.amount, ri.unit_code, mi.meal_type
 		FROM menu_items mi
-		JOIN saved_recipes sr ON sr.id = mi.recipe_id
-		WHERE mi.menu_plan_id = $1`, planID)
+		JOIN recipes rec ON rec.id = mi.recipe_id
+		JOIN recipe_ingredients ri ON ri.recipe_id = rec.id
+		WHERE mi.menu_plan_id = $1
+		ORDER BY ri.sort_order`, planID)
 	if err != nil {
 		return nil, fmt.Errorf("get ingredients by plan: %w", err)
 	}
@@ -268,24 +284,20 @@ func (r *Repository) GetIngredientsByPlan(ctx context.Context, planID string) ([
 
 	var result []ingredientRow
 	for rows.Next() {
-		var ingredientsRaw, nutritionRaw []byte
-		var mealType string
-		if err := rows.Scan(&ingredientsRaw, &nutritionRaw, &mealType); err != nil {
+		var row ingredientRow
+		if err := rows.Scan(&row.Name, &row.Amount, &row.UnitCode, &row.MealType); err != nil {
 			return nil, err
 		}
-		result = append(result, ingredientRow{
-			IngredientsJSON: ingredientsRaw,
-			NutritionJSON:   nutritionRaw,
-			MealType:        mealType,
-		})
+		result = append(result, row)
 	}
 	return result, rows.Err()
 }
 
 type ingredientRow struct {
-	IngredientsJSON []byte
-	NutritionJSON   []byte
-	MealType        string
+	Name     string
+	Amount   float64
+	UnitCode *string
+	MealType string
 }
 
 // --- helpers ---
@@ -304,3 +316,10 @@ func derefStr(s *string) string {
 	}
 	return *s
 }
+
+func derefFloat(f *float64) float64 {
+	if f == nil {
+		return 0
+	}
+	return *f
+}