箭头样式调整

main.py

@@ -589,10 +589,9 @@ class ArrowItem(DashboardItem):
         # 绘制连接线
         painter.drawLine(start, end)
 
-        # 绘制两端圆点（代替箭头）
+        # 绘制终点圆点（箭头指向）
         w = float(max(1, self._width))
-        dot_radius = max(4.0, min(12.0, 3.0 + w * 1.2))  # 圆点半径随线宽缩放
-        painter.drawEllipse(start, dot_radius, dot_radius)
+        dot_radius = max(4.0, min(12.0, 3.0 + w * 1.2))
         painter.drawEllipse(end, dot_radius, dot_radius)