为所有函数和类添加中文注释文档字符串

app/exercises/dead_bug/rules.py

@@ -4,10 +4,12 @@ from app.exercises.dead_bug.types import DeadBugMetrics, Point
 
 
 def has_required_visibility(landmarks: list[Point], required_indices: tuple[int, ...], visibility_threshold: float) -> bool:
+    """检查所有必需关键点的可见度是否高于阈值"""
     return all(landmarks[i].visibility >= visibility_threshold for i in required_indices)
 
 
 def detect_diagonal_extension(metrics: DeadBugMetrics) -> str | None:
+    """检测是否存在对角伸展（左臂+右腿 或 右臂+左腿）"""
     if metrics.left_leg_extended and metrics.right_leg_extended:
         return None
 
@@ -19,6 +21,7 @@ def detect_diagonal_extension(metrics: DeadBugMetrics) -> str | None:
 
 
 def is_ready_position(metrics: DeadBugMetrics) -> bool:
+    """判断是否处于准备姿态（膝盖弯曲且四肢未伸展）"""
     knees_bent = metrics.left_knee_angle <= 140 and metrics.right_knee_angle <= 140
     legs_not_extended = not metrics.left_leg_extended and not metrics.right_leg_extended
     return knees_bent and legs_not_extended and detect_diagonal_extension(metrics) is None