> When the mold is done, you let the agent pour in the code in any format you like.

Exactly. And the mold could be a spec, an MVP or even one of the implementations (e.g. the Swift one) acting as the source of truth for the other versions.

> "just" give them Claude and teach them to describe what they want and iterate to get something that maybe resembles an MVP but in more cases is just an interactive UI spec

That's a great example of what malleable code unlocks. You let the client to create the mold themselves, refine it and then use it to properly build the product.