chore: add String method for hand type

define/hands.go

@@ -6,3 +6,10 @@ const (
 	HAND_TYPE_LEFT  HandType = 0x28
 	HAND_TYPE_RIGHT HandType = 0x27
 )
+
+func (ht HandType) String() string {
+	if ht == HAND_TYPE_LEFT {
+		return "左手"
+	}
+	return "右手"
+}