Ok and how does it power that body and be able to move around the world in meatspace
If humans have managed it, I think its reasonable to assume a human level (or smarter) AI could accomplish the same bootstrapping process if you gave it access to an actuator (robot arm or human assistant), enough sensors to see whats going on, and some "starter" tools and materials.
What would be the minimum starter set of stuff it would need to get going? Way less stuff than what you'd find in a modern shop, or what anyone can order online with a few hundred dollars to spend.
If AIs learn to code, seems like they should be able to learn mechanical engineering too.
Also...