fix: capture and persist target object names for delete, outbound, and borrow operations in audit logs

inventory-backend/app/services/auth_service.py

@@ -317,9 +317,11 @@ class AuthService:
         if not user:
             raise Exception("用户不存在")
 
+        # 提前获取用户名用于审计日志
+        username = user.username
         db.session.delete(user)
         db.session.commit()
-        return True
+        return username
 
     @staticmethod
     def get_user_permissions(role_code):