feat: derive subject status from visits

backend/app/api/v1/visits.py

@@ -98,6 +98,7 @@ async def create_visit(
                 base_date=visit_in.planned_date,
                 visit_schedule=study.visit_schedule,
             )
+    subject = await subject_crud.sync_subject_status(db, subject)
     await audit_crud.log_action(
         db,
         study_id=study_id,
@@ -147,7 +148,6 @@ async def create_early_termination(
         db,
         subject,
         SubjectUpdate(
-            status="DROPPED",
             completion_date=termination_in.termination_date,
             drop_reason=reason,
         ),
@@ -192,6 +192,7 @@ async def update_visit(
     if visit_in.actual_date and visit.window_end and visit_in.actual_date > visit.window_end:
         raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="实际访视日期不能晚于访视窗口结束日期")
     updated = await visit_crud.update_visit(db, visit, visit_in)
+    await subject_crud.sync_subject_status(db, subject)
     detail = None
     if visit_in.status:
         detail = f"访视 {visit.visit_code} {visit.status} -> {visit_in.status}"
@@ -226,6 +227,7 @@ async def delete_visit(
     if not visit or visit.subject_id != subject_id or visit.study_id != study_id:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="访视不存在")
     await visit_crud.delete_visit(db, visit)
+    await subject_crud.sync_subject_status(db, subject)
     await audit_crud.log_action(
         db,
         study_id=study_id,