Repos can have precommit hooks, which are just executables (usually executable she'll scripts, but anything will do) that will run (as your user) on commit, checkout, etc.

I feel like this change is a far bigger one than thought, and it's gonna break some workflows, such as mine where I have a git repo that's shared between multiple "users" that I run applications as. I'm glad I've not gotten too far into this project. The next step is just to keep doing a pull/push cycle on every commit, but it's a bit more of a pain to make that happen.