Support collapsible trace nodes

[JLimperg]

The option to collapse/expand trace nodes is extremely helpful when navigating e.g. typeclass synthesis traces. But at least with my setup (Doom Emacs + lean4-mode), the traces are always fully expanded with no option to collapse them. Could we get this capability as well?

[Kha]

This would be great to have, but honestly I don't see anyone putting that much work into the Emacs mode, which would also feel like kind of a waste given the dearth of users. Probably the most realistic solution would be to get the entire HTML info view either inside or at least next to Emacs.

[JLimperg]

Fair. Have you looked into any of the Emacs HTML modules? (Emacs Application Framework seems to be the most developed one.)

[Kha]

I was only aware of the xwidget builtin that usually is not compiled in. EAF does look extensive, but also like a pain to install.