I would love to know myself. npub1j340qgfngwrx56vmaa0jutap7ezkx0qz2ty2gx0gnv7th8uyvxlqj0e2z5 (npub1j34…e2z5) has some hidden anti-email scraping code, but otherwise AI seems pretty impossible to block. I blocked Russia and Belarus at the CDN level, if only because Podnews is a US company and I didn’t want to break any trade block. (And, really, a capable CDN is the right way to block this but I understand you not wanting that).
I don’t suppose it helps, but https://podnews.net/AGENTS.md is there and a public file. (I should probably make it more visible in the sitemap).