Improve generated crossing geometry near sharp angles

> This case is fixed in a simple way, but it reveals more problems:
>
> `https://a-b-street.github.io/speedwalk/#19.95/52.7923616/13.2608191`
>
>
> We really need to handle the angle of roads better, or look for the "corner" in the generated sidewalks to place things better. (This might introduce more dependency of bulk operation steps, because then we have to generate sidewalks before crossing nodes.)
>

_Originally posted by @dabreegster in [#83](https://github.com/a-b-street/speedwalk/issues/83#issuecomment-3800028316)_

该 issue 提到了地图可视化中锐角附近交叉几何图形的视觉问题。首先检查链接的 URL，以查看渲染问题。查找生成人行道和交叉节点的代码，这些代码可能位于几何处理或渲染模块中。了解人行道生成与交叉节点放置之间的依赖关系是关键。“完成”意味着改进交叉几何图形，同时不破坏现有功能。

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