Here's what's happening:

NodeJS's implementation of TiddlyWiki is based on files. If I'm not mistaken, there are alternative means to have a TiddlyWiki: the simplest is just a (very large) .html file with all the resources. But that's not my case: I use NodeJS's.

My local TiddlyWiki instance is a very complete full-stack solution that I run as a service, always available through my browser. It is incredibly rich in features.

I do not make all my content public, as much of this is personal and with little to no relevance to anyone else. But TiddlyWiki has a command-line feature to render tiddlers: in particular, tiddlers can be filtered by tags and rendered to .html files. That is what the public-eng tag is for, by the way: all of the other, untagged content, is private and won't get exported (and that is why there are so many clicable dead-ends — sorry about that!). So my process is just to render the .html files and serve it on a remote server. It's all static files, which is sort of cool.

With time, I realised images in Tiddlywiki are tricky, and that opened a bit of a rabbithole which led to some other improvements in how I handle things. At the moment, the core routine is done (and working!) with a few minor improvements to make (at a much later stage – I want to do something else now).