> I wonder how hard it would be to get an agent to send me a text message if it gets stuck on something.

Not too hard, aka. I have a friend who did this. Rather than a text message, he uses IRC, but the effect should be the same. IRC is probably a little better.

Assuming you use Claude Code, the concept to look for is 'channels'. It's described as being for sending messages to Claude, but they work both ways. And I see one of the canned channels is iMessage.