So how does it do it?

I haven't read this particular code, I did some analysis of various prompts it uses, I didn't hear about anything specific like this. Mostly wanted to say "it's at least possible to dig into it if you'd like," not that I had the answer directly.

Couldn’t you have claude itself de-minify it?

Maybe. It’s not something I have enough of an interest in to out the time into trying it out.