Automate weekly pull?

Not a bug. A question.

Background: For now I mostly want to use local to track changes to my site. Most of the problems on my site come from plugins that get updated and break something else. As a recovering programmer, I want diffs. My evil plan: pull the site once a week. Run a git commit and use that track diffs. Then when we notice something is broken, I just need to walk back through the logs to see which plugin might have broken things.

I’m working on MacOS. In the worst case I could automate the whole shebang through Keyboard Maestro or BetterTouchTool. However that will be very fragile. Is there a more elegant solution? (heck I could use a BASH/ZSH script - although my unix skills are rusty).