bug#81520: Add pre-receive hook to Savannah to reject LLM-encumbered commits

> From: Sean Whitton <[email protected]>
> Cc: [email protected]
> Date: Thu, 30 Jul 2026 18:36:19 +0100
> 
> Jim Porter [30/Jul 10:31am -07] wrote:
> > I spent a little while researching options here, and the most common
> > annotation is "Co-Authored-By: Some LLM <[email protected]>" followed
> > by "Assisted-By: Some LLM". (The perhaps controversially named Kompromat
> > site[1] links many examples and describes their detection criteria,
> > which I've used as the basis of my implementation.)
> >
> > Unfortunately, in the Co-Authored-By case, ordinary humans are often
> > co-authors, and there are a few commits in GNU Emacs master that already
> > use Co-Authored-By to indicate multiple people worked on the commit. I
> > think this is generally a good practice, since it makes the copyright
> > situation explicit when multiple people have done legally-significant
> > amounts of work in a single commit.
> >
> > If we want to permit using Co-Authored-By to list people, then I think
> > the only option for detecting LLMs is using their email addresses.
> > Luckily, the addresses themselves seem to be stable, though of course
> > this list only covers the most popular options. That said, the vast
> > majority of money spent on SaaSS LLMs goes to one of the listed providers.
> 
> We explicitly permit it in CONTRIBUTE.

And I never liked it, because it doesn't fit the attributions in
ChangeLog files.

> So yeah, let's match on e-mail addresses.

Sorry, I'm firmly against that, for the reasons I already explained.
I'd rather we disallowed Co-Authored-By and other similar headings.