AI generated art with human steering is copyrightable [1].
Agentic code development is human steering, thus copyrightable under the same grounds.
Open source code is copyrighted, otherwise we would be talking about public domain.
When you edit something in the public domain to enrich it, it then becomes copyrightable again.
[1] https://news.artnet.com/art-world/invoke-snags-first-ai-imag...
It's legally untested, so we can't be sure one way or the other. But people definitely seem to assume that's the case.
There's still something dark at the center; a lawless visciousness to the new era.
You can't apply naïve transitive reasoning to law. Law is not code. Your assertions are meaningless and unsupported noise until they're actually tried in a court.