修复加减分失败但计入记录和添加导出功能

backend/services/attendance_service.py

@@ -75,10 +75,15 @@ class AttendanceService:
                 points_change = -settings.DEDUCTION_ATTENDANCE_LATE
             else:
                 points_change = -settings.DEDUCTION_ATTENDANCE_LEAVE
-            
             # 创建扣分记录
             student = await StudentModel.get_by_id(student_id)
             if student:
+                # 检查分数是否会超出范围（防止溢出）
+                current_points = student.get("total_points", 0)
+                new_points = current_points + points_change
+                if new_points < 0:
+                    return {"success": False, "message": f"分数不能为负（当前{current_points}，扣{abs(points_change)}）"}
+                
                 # 获取操作人姓名
                 user = await UserModel.get_by_user_id(recorder_id)
                 recorder_name = user.get("real_name", "班主任") if user else "班主任"
@@ -99,6 +104,7 @@ class AttendanceService:
                 
                 # 标记已应用扣分
                 await AttendanceModel.mark_deduction_applied(attendance_id)
+                await AttendanceModel.mark_deduction_applied(attendance_id)
         
         logger.info(f"用户[{recorder_id}] 添加考勤记录[{attendance_id}] -> {status}")