> how do you trust the code claude wrote?

If that's something you're worried about, review the code before running it.

> don't you get anxiety "what if there's an error in tui code and it would mess up my git repo"?

I think you might want to not run untrusted programs in an environment like that, alternatively find a way of start being able to trust the program. Either approaches work, and works best depending on what you're trying to do.