Because the contents of all of the files are serialized into the URL, you can already just use the browser's refresh button for this, which seems sufficient to me.

Reloading the browser page will trigger re-fetching resources (compiler, bundler, imported modules, etc) and their initialization. The workaround with a space is more efficient and sometimes even faster.

I can relate to this. I'd even venture to suggest intercepting Cmd+R/Ctrl-R keypresses while the output window is focused (maybe that's a step too far).

Design question though: where should the button go? It doesn't really make sense to have it in the space to the right of 'AST Output' since it only applies to the 'Result' tab, and it can't obscure the content. Maybe inside the 'Result' button?

I also think it should be inside the Result button. Otherwise, it becomes unclear what it reloads.

It should be moved to svelte.dev repo.