I've used opencode on a plane with local models to make small updates to local MacOS apps. It's not fast or amazing, but it does work well enough to do trivial changes.

But also yes this is a real concern.

What bad things to you anticipate Anthropic doing with your secrets, env vars, and certificates?

Not if you've got a good sandbox.

What could go wrong? Might Apple change something across five ecosystems and leave you in the lurch, and now you have to go through all the slop to try to fix it?