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

backend/apps/notify/serializers.py

@@ -0,0 +1,27 @@
+from rest_framework import serializers
+from apps.core.serializers import AsyncModelSerializer
+from .models import Notification, AlertRule
+
+
+class NotificationSerializer(AsyncModelSerializer):
+    category_name = serializers.CharField(source="get_category_display", read_only=True)
+
+    class Meta:
+        model = Notification
+        fields = [
+            "id", "title", "content", "category", "category_name",
+            "link", "is_read", "read_at", "extra_data", "created_at",
+        ]
+        read_only_fields = ["id", "created_at"]
+
+
+class AlertRuleSerializer(AsyncModelSerializer):
+    rule_type_name = serializers.CharField(source="get_rule_type_display", read_only=True)
+
+    class Meta:
+        model = AlertRule
+        fields = [
+            "id", "code", "name", "rule_type", "rule_type_name",
+            "threshold", "is_enabled", "channels", "created_at", "updated_at",
+        ]
+        read_only_fields = ["id", "created_at", "updated_at"]