feat(category): add min_price and max_price to serializer

enable retrieval of min and max product prices for categories to support price range filters. fixed a typo in queryset filter for brands.

engine/core/models.py

@@ -456,8 +456,8 @@ class Category(NiceModel, MPTTModel):
     @cached_property
     def brands(self) -> QuerySet["Brand"]:
         return Brand.objects.filter(
-            products__category=self,
-            products__is_active=True,
+            product__category=self,
+            product__is_active=True,
             is_active=True,
         ).distinct()
 

engine/core/serializers/detail.py

@@ -62,6 +62,8 @@ class CategoryDetailSerializer(ModelSerializer):
     children = SerializerMethodField()
     filterable_attributes = SerializerMethodField()
     brands = BrandSimpleSerializer(many=True, read_only=True)
+    min_price = SerializerMethodField()
+    max_price = SerializerMethodField()
 
     class Meta:
         model = Category
@@ -98,6 +100,12 @@ class CategoryDetailSerializer(ModelSerializer):
             return list(serializer.data)
         return []
 
+    def get_min_price(self, obj: Category):
+        return obj.min_price
+
+    def get_max_price(self, obj: Category):
+        return obj.max_price
+
 
 class BrandDetailSerializer(ModelSerializer):
     categories = CategorySimpleSerializer(many=True)