feat(backend): add heroImageUrl and tags to RecipeSummaryResponse

GET /v1/recipes was returning RecipeSummaryResponse with no tags and
only heroImagePreview. The planner frontend needs protein tags to pick
gradient backgrounds for tiles without a hero image.

- Replace JPQL constructor projection with entity query + LEFT JOIN FETCH tags
- Map Recipe entity to RecipeSummaryResponse in service (includes tags + heroImageUrl)
- Drop heroImagePreview in favour of heroImageUrl on the summary DTO

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

backend/src/main/java/com/recipeapp/recipe/RecipeRepository.java

@@ -1,6 +1,5 @@
 package com.recipeapp.recipe;
 
-import com.recipeapp.recipe.dto.RecipeSummaryResponse;
 import com.recipeapp.recipe.entity.Recipe;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Query;
@@ -17,9 +16,8 @@ public interface RecipeRepository extends JpaRepository<Recipe, UUID> {
     List<Recipe> findByHouseholdIdAndDeletedAtIsNull(UUID householdId);
 
     @Query("""
-            SELECT new com.recipeapp.recipe.dto.RecipeSummaryResponse(
-                r.id, r.name, r.serves, r.cookTimeMin, r.effort, r.heroImagePreview)
-            FROM Recipe r
+            SELECT r FROM Recipe r
+            LEFT JOIN FETCH r.tags
             WHERE r.household.id = :householdId
               AND r.deletedAt IS NULL
               AND (:search IS NULL OR LOWER(r.name) LIKE LOWER(CONCAT('%', CAST(:search AS string), '%')))
@@ -27,7 +25,7 @@ public interface RecipeRepository extends JpaRepository<Recipe, UUID> {
               AND (:cookTimeMaxMin IS NULL OR r.cookTimeMin <= :cookTimeMaxMin)
             ORDER BY r.createdAt DESC
             """)
-    List<RecipeSummaryResponse> findFiltered(
+    List<Recipe> findFiltered(
             @Param("householdId") UUID householdId,
             @Param("search") String search,
             @Param("effort") String effort,

backend/src/main/java/com/recipeapp/recipe/RecipeService.java

@@ -42,7 +42,15 @@ public class RecipeService {
     @Transactional(readOnly = true)
     public List<RecipeSummaryResponse> listRecipes(UUID householdId, String search, String effort,
                                                     Integer cookTimeMaxMin, String sort, int limit, int offset) {
-        return recipeRepository.findFiltered(householdId, search, effort, cookTimeMaxMin, sort, limit, offset);
+        return recipeRepository.findFiltered(householdId, search, effort, cookTimeMaxMin, sort, limit, offset)
+                .stream()
+                .map(r -> new RecipeSummaryResponse(
+                        r.getId(), r.getName(), r.getServes(), r.getCookTimeMin(), r.getEffort(),
+                        r.getHeroImageUrl(),
+                        r.getTags().stream()
+                                .map(t -> new TagResponse(t.getId(), t.getName(), t.getTagType()))
+                                .toList()))
+                .toList();
     }
 
     @Transactional(readOnly = true)

backend/src/main/java/com/recipeapp/recipe/dto/RecipeSummaryResponse.java

@@ -1,5 +1,6 @@
 package com.recipeapp.recipe.dto;
 
+import java.util.List;
 import java.util.UUID;
 
 public record RecipeSummaryResponse(
@@ -8,5 +9,6 @@ public record RecipeSummaryResponse(
         short serves,
         short cookTimeMin,
         String effort,
-        String heroImagePreview
+        String heroImageUrl,
+        List<TagResponse> tags
 ) {}