调整账号注册与删除流程

backend/app/api/v1/users.py

@@ -1,6 +1,7 @@
 import uuid
 
 from fastapi import APIRouter, Depends, HTTPException, Query, status
+from sqlalchemy.exc import IntegrityError
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.core.deps import get_db_session, is_system_admin, require_roles
@@ -97,4 +98,16 @@ async def delete_user(
             status_code=status.HTTP_400_BAD_REQUEST,
             detail="该账号仍在项目成员中，请先在项目成员配置中移除后再删除",
         )
-    await user_crud.delete_user(db, db_user)
+    if await user_crud.user_has_retained_history(db, db_user.id):
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="该账号已有审计或权限访问记录，请停用账号以保留历史追溯",
+        )
+    try:
+        await user_crud.delete_user(db, db_user)
+    except IntegrityError as exc:
+        await db.rollback()
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="该账号已有业务记录，请停用账号以保留历史追溯",
+        ) from exc