baseline: 批次A-D 成果 + membership 半成品（测试红）

backend/apps/catalog/serializers.py

@@ -0,0 +1,50 @@
+"""商品中心序列化器（async 兼容）。"""
+
+from rest_framework import serializers
+from apps.core.serializers import AsyncModelSerializer
+from .models import Category, Brand, Unit, Product
+
+
+class CategorySerializer(AsyncModelSerializer):
+    parent_code = serializers.CharField(source="parent.code", read_only=True, default=None)
+
+    class Meta:
+        model = Category
+        fields = [
+            "id", "code", "name", "parent_code", "sort_order",
+            "is_deleted", "created_at", "updated_at",
+        ]
+        read_only_fields = ["id", "created_at", "updated_at"]
+
+
+class BrandSerializer(AsyncModelSerializer):
+    class Meta:
+        model = Brand
+        fields = ["id", "code", "name", "logo_url", "is_deleted", "created_at", "updated_at"]
+        read_only_fields = ["id", "created_at", "updated_at"]
+
+
+class UnitSerializer(AsyncModelSerializer):
+    class Meta:
+        model = Unit
+        fields = ["id", "code", "name", "is_base", "is_deleted", "created_at", "updated_at"]
+        read_only_fields = ["id", "created_at", "updated_at"]
+
+
+class ProductSerializer(AsyncModelSerializer):
+    category_code = serializers.CharField(source="category.code", read_only=True, default=None)
+    brand_code = serializers.CharField(source="brand.code", read_only=True, default=None)
+    base_unit_code = serializers.CharField(source="base_unit.code", read_only=True, default=None)
+    base_unit_name = serializers.CharField(source="base_unit.name", read_only=True, default=None)
+
+    class Meta:
+        model = Product
+        fields = [
+            "id", "code", "name", "spec", "barcode",
+            "category_code", "brand_code", "base_unit", "base_unit_code", "base_unit_name",
+            "cost_price", "sale_price", "min_sale_price", "tax_rate",
+            "is_batch_managed", "shelf_life_days",
+            "status", "ext_data", "source_channel",
+            "is_deleted", "created_at", "updated_at",
+        ]
+        read_only_fields = ["id", "created_at", "updated_at"]