feat: add profile and defalt hospital

apps/organization/serializers.py

@@ -25,7 +25,16 @@ class CmsInstitutionSerializer(serializers.ModelSerializer):
             'id', 'code', 'name', 'type', 'level',
             'province', 'city', 'banner_url', 'created_at', 'updated_at',
         ]
-        read_only_fields = ['id', 'created_at', 'updated_at']
+        # type 不可编辑：新增/编辑均不接收，存库恒为 hospital（见 create/update）
+        read_only_fields = ['id', 'type', 'created_at', 'updated_at']
+
+    def create(self, validated_data):
+        validated_data['type'] = 'hospital'
+        return super().create(validated_data)
+
+    def update(self, instance, validated_data):
+        validated_data['type'] = 'hospital'   # 每次保存都归一为 hospital
+        return super().update(instance, validated_data)
 
     def to_representation(self, instance):
         data = super().to_representation(instance)