alt Hacker NewsThere's Tina CMS for editing files in Git, but honestly editing flat files is probably the least interesting or complicated part of an enterprise CMS, and IMO there's rarely a good reason to interact with files directly versus a database that publishes files.
I ran git-based blogs for years and have gone back to CMS. The instant preview and the instant publishing really make it a lot more pleasant to work with it. With Git, my read-eval-print loop so to say was a minute which is just too long. Fixing a typo then takes 2 minutes.