feat(category): add brands relationship and resolve method

enable brands association with categories and allow querying of active brands within a category. Updated GraphQL schema, models, and serializers to include this relationship while deprecating redundant category-to-brand ManyToManyField.

engine/core/admin.py

@@ -421,10 +421,7 @@ class BrandAdmin(
         "priority",
         "is_active",
     )
-    list_filter = (
-        "categories",
-        "is_active",
-    )
+    list_filter = ("is_active",)
     search_fields = (
         "uuid",
         "name",

engine/core/graphene/object_types.py

@@ -230,6 +230,7 @@ class CategoryType(DjangoObjectType):
             "minimum and maximum prices for products in this category, if available."
         ),
     )
+    brands = List(lambda: BrandType, description=_("brands in this category"))
     tags = DjangoFilterConnectionField(
         lambda: CategoryTagType, description=_("tags for this category")
     )
@@ -249,6 +250,7 @@ class CategoryType(DjangoObjectType):
             "slug",
             "description",
             "image",
+            "brands",
             "min_max_prices",
         )
         filter_fields = ["uuid"]
@@ -294,6 +296,9 @@ class CategoryType(DjangoObjectType):
             "max_price": min_max_prices["max_price"],
         }
 
+    def resolve_brands(self: Category, info) -> QuerySet[Brand]:
+        return self.brands
+
     def resolve_seo_meta(self: Category, info):
         lang = graphene_current_lang()
         base = f"https://{settings.BASE_DOMAIN}"

engine/core/models.py

@@ -443,6 +443,14 @@ class Category(ExportModelOperationsMixin("category"), NiceModel, MPTTModel):
         # Fallback to favicon.png from static files
         return static("favicon.png")
 
+    @cached_property
+    def brands(self) -> QuerySet["Brand"]:
+        return Brand.objects.filter(
+            products__category=self,
+            products__is_active=True,
+            is_active=True,
+        ).distinct()
+
     class Meta:
         verbose_name = _("category")
         verbose_name_plural = _("categories")
@@ -490,8 +498,8 @@ class Brand(ExportModelOperationsMixin("brand"), NiceModel):
     categories = ManyToManyField(
         "core.Category",
         blank=True,
-        help_text=_("optional categories that this brand is associated with"),
-        verbose_name=_("associated categories"),
+        help_text=_("DEPRECATED"),
+        verbose_name=_("DEPRECATED"),
     )
     slug = AutoSlugField(
         populate_from=("name",),

engine/core/serializers/detail.py

@@ -26,6 +26,7 @@ from engine.core.models import (
     Wishlist,
 )
 from engine.core.serializers.simple import (
+    BrandSimpleSerializer,
     CategorySimpleSerializer,
     ProductSimpleSerializer,
 )
@@ -60,6 +61,7 @@ class CategoryDetailListSerializer(ListSerializer):
 class CategoryDetailSerializer(ModelSerializer):
     children = SerializerMethodField()
     filterable_attributes = SerializerMethodField()
+    brands = BrandSimpleSerializer(many=True, read_only=True)
 
     class Meta:
         model = Category
@@ -71,6 +73,7 @@ class CategoryDetailSerializer(ModelSerializer):
             "image",
             "markup_percent",
             "filterable_attributes",
+            "brands",
             "children",
             "slug",
             "created",