未知（继上次中断）

backend/app/api/v1/visits.py

@@ -40,6 +40,7 @@ async def list_visits(
     db: AsyncSession = Depends(get_db_session),
 ) -> list[VisitRead]:
     await _ensure_subject(db, study_id, subject_id)
+    await visit_crud.mark_overdue_as_lost(db, subject_id)
     visits = await visit_crud.list_visits(db, subject_id)
     return list(visits)
 
@@ -61,15 +62,18 @@ async def create_visit(
     await _ensure_subject_active(db, subject)
     if visit_in.subject_id != subject_id:
         raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="参与者不匹配")
+    next_visit_code = await visit_crud.get_next_visit_code(db, subject_id)
+    if next_visit_code == "V1" and not visit_in.planned_date:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="首次新增访视必须填写计划访视日期")
     visit = await visit_crud.create_visit(
         db,
         study_id=study_id,
         visit_in=visit_in,
         subject=subject,
-        visit_code=visit_in.visit_code,
+        visit_code=next_visit_code,
         planned_date=visit_in.planned_date,
     )
-    if visit_in.visit_code == "V1" and visit_in.planned_date:
+    if next_visit_code == "V1" and visit_in.planned_date:
         study = await study_crud.get(db, study_id)
         if study:
             await visit_crud.create_followup_visits(