If you just combine Working Copy (of which I'm a huge fan) and github actions to build the site on merge to main, you get simple setup that really should do the trick for updates to a static site.
Yep, I use Working Copy with both Jekyll and 11ty sites on Netlify to do the same thing.
Even made a Shortcuts action to create new posts - it formats the YAML frontmatter, inserts the date, asks for title, then creates a new document in Working Copy with the proper file path. Super useful.
Working Copy is a fantastic combined Git client and text editor, which I've used extensively to edit my own website, and Secure ShellFish from the same developer is a great SSH client, file manager and editor.