Looks very interesting. I am currently researching node-based developer tools and libraries, and after a quick look at your code I wonder why you chose to create your UI from scratch instead of using a diagramm-ish utility (react-flow and many others)? I know there are some tradeoffs with each, like one might be geared toward drawing, another for graph visualization, another for lots of nodes etc, and so maybe you didn’t like these tradeoffs?
btw, https://deepwiki.com/flydelabs/flyde