I have one setup. The setup was abit clunky since cli work is required. But after that I had a great experience.

I have markdown files in a git repo and run mdbook via cicd so I get a nice html build. Localy I can build it too or just use the markdown files (except for mdbook specific features such as preprocessors).

How secure is the password protection?

That would chsnge nothing, simce they would also be on the hard drive.