The plugin just put the node list as a widget, then I modified its templates to merge it with the navigation system.
The plugin isn't mine, it's called "Nodelistsidebar".
Hello,
Putting the forums in the navigation can be done with the help of a third-party add-on and I can modify it to match the Flarum software, if you’re interested DM me.
Regards
Refreshed design.
Node icon/image size control.
The collapsible categories issue occurs when there are many categories.
Sticky use info added.
Minor layout enhancements.