修复前后端显示异常问题（受试者、中心、负责人、日期等）

backend/app/schemas/member.py

@@ -3,6 +3,7 @@ from datetime import datetime
 from typing import Literal, Optional
 
 from pydantic import BaseModel, ConfigDict, Field
+from app.schemas.user import UserDisplay
 
 StudyRole = Literal["PM", "CRA", "PV", "IMP", "ADMIN"]
 
@@ -27,3 +28,7 @@ class StudyMemberRead(BaseModel):
     added_at: datetime
 
     model_config = ConfigDict(from_attributes=True)
+
+
+class StudyMemberReadWithUser(StudyMemberRead):
+    user: Optional[UserDisplay] = None