为所有函数和类添加中文注释文档字符串

app/rendering/overlay_renderer.py

@@ -7,6 +7,7 @@ from app.exercises.dead_bug.types import DeadBugResult
 
 
 def draw_status_overlay(image: np.ndarray, result: DeadBugResult) -> None:
+    """在图像上叠加动作状态信息（次数、阶段、反馈）"""
     color = (60, 220, 90) if result.is_standard else (50, 180, 255)
     cv2.rectangle(image, (12, 12), (520, 142), (20, 20, 20), -1)
     cv2.putText(image, f"Dead bug reps: {result.rep_count}", (28, 48), cv2.FONT_HERSHEY_SIMPLEX, 0.9, color, 2)

app/rendering/skeleton_renderer.py

@@ -18,6 +18,7 @@ def draw_landmarks(
     line_thickness: int = 2,
     point_radius: int = 4,
 ) -> None:
+    """绘制人体骨架关键点与连接线（仅绘制可见度达标的点）"""
     if connections is None:
         connections = _POSE_CONNECTIONS
 

app/rendering/window_display.py

@@ -6,16 +6,20 @@ WINDOW_NAME = "Android Camera (WebRTC)"
 
 
 def show_frame(image, window_name: str = WINDOW_NAME) -> None:
+    """在OpenCV窗口中显示图像帧"""
     cv2.imshow(window_name, image)
 
 
 def wait_key(delay_ms: int = 1) -> int:
+    """等待按键并返回ASCII码"""
     return cv2.waitKey(delay_ms) & 0xFF
 
 
 def is_esc_pressed() -> bool:
+    """检测ESC键是否被按下"""
     return wait_key(1) == 27
 
 
 def close_window() -> None:
+    """关闭所有OpenCV窗口"""
     cv2.destroyAllWindows()