refactor(ptz_person_tracker): 禁用默认图片保存，调整save_image默认值为False

- 修改PTZPersonDetector初始化时save_image参数默认值为False
- 取消默认启用图片保存，减少运行时磁盘IO负担
- 其他代码逻辑和功能保持不变，确保兼容性和稳定性

dual_camera_system/ptz_person_tracker.py

@@ -66,7 +66,7 @@ class PTZPersonDetector:
     
     def __init__(self, model_path: str = None, model_type: str = 'auto',
                  confidence_threshold: float = 0.5, use_gpu: bool = False,
-                 save_image: bool = True, image_dir: str = '/home/admin/dsh/ptz_detection_images'):
+                 save_image: bool = False, image_dir: str = '/home/admin/dsh/ptz_detection_images'):
         """
         初始化检测器
         Args: