you’re using Kirby so I’m not sure how file system based CMS and Git integrate.
Actually, Kirby is a better candidate for a pure-git workflow than most CMS’s, because it’s all files. Just author your new files, git add, git commit, git push to your server.
git is very portable, as well. If you have a working copy of your website, the
.git folder is there too. If you don’t have a copy, just git clone and now you do. You could even have a “testing” branch alongside your “production” branch on the server.