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.

For backking up files I can recommend restic. It encrypts and compresses your backup. At the same time it does deduplication. So if you backup a file twice, it takes only the space of one. If you are lucky it will even do that for oaets of a file. Although it only has a cli.

It seems a bit off that the only accept code via mail but host the repo with forgejo and have a lot of open PRs.