style: add detection job docstring

Agent-Logs-Url: https://github.com/IBB666/IBB_POSE/sessions/c9c0cbf1-b9de-4070-b7ee-8bda69755661

Co-authored-by: kukulu00 <1170651+kukulu00@users.noreply.github.com>

ibb_pose_nodes.py

@@ -873,6 +873,8 @@ class IBBPoseProcessor:
     
     # 一个简单的数据类，用于跟踪检测到的人
     class DetectionJob:
+        """Track one detected person crop through preprocessing, inference, and restore."""
+
         def __init__(self, frame_idx, person_idx, input_tensor, crop_info):
             self.frame_idx = frame_idx
             self.person_idx = person_idx