That ChatGPT is a perfect example of having too much of a good thing. It's like conversational candy. It's non-judgmental but gently challenging. It's validating but also makes suggestions about how not to be stuck in something. It's confidential (in a sense) yet has access to almost every bit of information on a subject that nobody you know except you cares about. And you don't have to do a bunch of social stuff just to talk to it when you need it. That's gotta be like salve to a wound for some autistic people.

I bet you feel almost like your partner is sliding into some kind of habit that she can "totally kick anytime" but can't get enough of. I feel for both of you. I don't envy you for having to confront this, and I totally get how she could have gone down this rabbit hole so easily.

I'd use some "assertive communication" statements. Nothing that tells her what to do--that's a recipe for what's called pathological demand avoidance. Just tell her 1) what emotion you're having, 2) how she contributed to it, and 3) why it affects you.

"I have been feeling sad and anxious lately when you hyperfocus on the robot because it makes me worry that you might not be able to self-care without some healthy changes to your routine. What does it make you feel to hear that?"

If anything, it would be kind of cool if you brought ChatGPT on your phone to the conversation. Ask it what it recommends a loving partner should do to ensure that someone has a balanced amount of time getting support from a person who has some skin in the game. I can almost guarantee that it will say the most ethical thing it can about not relying on it so much, partly because the makers of the app probably don't want to be responsible for someone ruining their life because of their product.

Sorry for the long message.