I'm not sure what "AI-native" would mean but GT has LLM-integrations, support for working in distributed systems and a COBOL-bridge that has been used in managing transitions of legacy systems.

Here's a talk about it:

https://www.youtube.com/watch?v=W8TSPED0alY

If you load the code referenced here, https://book.gtoolkit.com/analyzing-cobol--the-aws-carddemo-... , you can explore the demo used in the talk.

I'm sure you'll manage to figure out the LLM-integrations.

Edit: The Feenk folks also have a structured theory for why and how to do these things that they've spent a lot of time and experience on refining, visualising and developing tooling around.

I think it is a good idea for anyone working with large legacy systems to have such a theoretical foundation for how to communicate, approach problems and evaluate progress. Without it one is highly likely to make expensive decisions based on gut feeling and vague assumptions.