But I also think that if a maintainer asks you to jump before submitting a PR, you politely ask, “how high?”
If trust didn't matter, there wouldn't have been a need for the Linux Kernel team to ban the University of Minnesota for attempting to intentionally smuggle bugs through the PR process as part of an unauthorized social experiment. As it stands, if you / your PRs can't be trusted, they should not even be admitted to the review process.
No you don’t. You can’t outsource trust determinations. Especially to the people you claim not to trust!
You make the judgement call by looking at the code and your known history of the contributor.
Nobody cares if contributors use an LLM or a magnetic needle to generate code. They care if bad code gets introduced or bad patches waste reviewers’ time.
Stop trying to equate LLM-generated code with indexing-based autocomplete. They’re not the same thing at all: LLM-generated code is equivalent to code copied off Stack Overflow, which is also something you’d better not be attempting to fraudulently pass off as your own work.
For example, you either make your contributors attest that their changes are original or that they have the right to contribute their changes—or you assume this of them and consider it implicit in their submission.
What you (probably) don’t do is welcome contributions that the contributors do not have the right to make.