It uses completely different software (that I wrote together with a small team of volunteers: https://codeberg.org/git-pages/git-pages) which scales very well horizontally and works more like GitHub Pages than Codeberg Pages technically, but in concept you are basically correct.

I started using Codeberg 2 months ago and I'm shocked how great and simple is it!

Highly recommended, especially if you actually hate keys instead of passwords ;)

Yup, you can use something like:

$ curl http://yourdomain.org -X PUT --data https://tangled.org/@yourname.tangled.sh/site

from a CI pipeline, or just upload an archive from the same (if you use "Method B" for authorization).