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

backend/apps/partner/serializers.py

@@ -0,0 +1,66 @@
+"""partner 序列化器（async 兼容）。"""
+
+from rest_framework import serializers
+from apps.core.serializers import AsyncModelSerializer
+from .models import PriceLevel, Contact, Customer, Supplier
+
+
+class PriceLevelSerializer(AsyncModelSerializer):
+    class Meta:
+        model = PriceLevel
+        fields = [
+            "id", "code", "name", "discount_rate", "sort_order",
+            "is_deleted", "created_at", "updated_at",
+        ]
+        read_only_fields = ["id", "created_at", "updated_at"]
+
+
+class ContactSerializer(AsyncModelSerializer):
+    customer_code = serializers.CharField(source="customer.code", read_only=True, default=None)
+    supplier_code = serializers.CharField(source="supplier.code", read_only=True, default=None)
+
+    class Meta:
+        model = Contact
+        fields = [
+            "id", "name", "phone", "email", "title", "is_primary",
+            "customer_code", "supplier_code",
+            "is_deleted", "created_at", "updated_at",
+        ]
+        read_only_fields = ["id", "created_at", "updated_at"]
+
+
+class CustomerSerializer(AsyncModelSerializer):
+    price_level_code = serializers.CharField(source="price_level.code", read_only=True, default=None)
+    balance = serializers.SerializerMethodField()
+
+    class Meta:
+        model = Customer
+        fields = [
+            "id", "code", "name", "kind", "contact_name", "phone", "email",
+            "address", "tax_number", "bank_account",
+            "price_level_code", "credit_limit", "initial_receivable",
+            "is_active", "remark", "balance",
+            "is_deleted", "created_at", "updated_at",
+        ]
+        read_only_fields = ["id", "created_at", "updated_at", "balance"]
+
+    def get_balance(self, obj):
+        # 阶段 2 接入应收模块后实算
+        return str(obj.initial_receivable)
+
+
+class SupplierSerializer(AsyncModelSerializer):
+    balance = serializers.SerializerMethodField()
+
+    class Meta:
+        model = Supplier
+        fields = [
+            "id", "code", "name", "contact_name", "phone", "email",
+            "address", "tax_number", "bank_account",
+            "initial_payable", "is_active", "remark", "balance",
+            "is_deleted", "created_at", "updated_at",
+        ]
+        read_only_fields = ["id", "created_at", "updated_at", "balance"]
+
+    def get_balance(self, obj):
+        return str(obj.initial_payable)