docs: Update AI usage policy

The previous policy was primarily written from a standpoint
that AI models are not very good and we didn't wanna waste any
time reviewing PRs generated by AI. Now that AI models have become
actually good and their output is just as good as regular contributions,
let's stop requiring the disclosure as its pointless to still have it,
it doesn't really matter anymore whether a patch was written with or without
AI. It's up to the author to make sure they're not wasting our time by 
submitting unreviewed, untested code upstream, regardless of whether that
code is written by an AI or not.

The new policy is inspired by https://github.com/lxc/incus/pull/3506, with
various removals to be less adverse to the usage of AI.

AGENTS.md

@@ -3,6 +3,11 @@
 This file provides guidance to AI coding agents when working with code in this repository. Only add
 instructions to this file if you've seen an AI agent mess up that particular bit of logic in practice.
 
+## Legal
+
+ - Only human beings can ever be credited within commit messages. This means no Co-Developed-By or
+   Co-Authored-By or anything similar that lists an AI model instead of a human being.
+
 ## Key Documentation
 
 Always consult these files as needed:
@@ -35,9 +40,3 @@ display. This is critical for diagnosing build and test failures.
 ## Pull Request Review Instructions
 
 - Always check out the PR in a git worktree in `worktrees/`, review it locally and remove the worktree when finished.
-
-## AI Contribution Disclosure
-
-Per project policy: if you use AI code generation tools, you **must disclose** this in commit messages
-by adding e.g. `Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>`.
-All AI-generated output requires thorough human review before submission.

docs/CONTRIBUTING.md

@@ -50,22 +50,30 @@ See [reporting of security vulnerabilities](https://systemd.io/SECURITY).
 * Github will automatically add the `please-review` label when a pull request is opened or updated.
   If you need more information after a review, you can comment `/please-review` on the pull request to have Github add the `please-review` label to the pull request.
 
-## Using AI Code Generators
+## Policy on the use of Large Language Models (LLMs) and AI tooling
 
-If you use an AI code generator such as ChatGPT, Claude, Copilot, Llama or a similar tool, this must be
-disclosed in the commit messages by adding e.g. `Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>`
-and pull request description.
+We expect everyone contributing to systemd to fully own their
+contribution, be able to reason about it, be able to explain why things
+were done a particular way and act as the full owner of that code. AI
+tools are treated the same as traditional tooling like `sed`, `awk` or
+`coccinelle`.
 
-The quality bar for contributions to this project is high, and unlikely to be met by an unattended AI tool,
-without significant manual corrections. Always thoroughly review and correct any such outputs, for example
-ensuring it accurately follows [Coding Style](https://systemd.io/CODING_STYLE) at the very minimum. Please do
-not fire-and-forget pull requests without any human intervention and review, as that will likely result in
-low-quality results that will not be accepted, and if done repeatedly, may result in the account being
-blocked. As with any other submissions, authors are responsible for doing due diligence and ensuring their
-submissions are compatible with the project's license as documented in LICENSES/README.md.
+For the purpose of this project, AI tools CANNOT be treated as author,
+co-author or be credited in any way that would suggest any ownership
+over the contribution.
 
-As a guideline, if someone notices that a contribution (code, issues, comments) was made with the help of AI,
-there was likely a lack of human review of the AI generated output.
+The contributor should have done all the thinking, planning and
+understanding of the changes needed to resolve an issue or implement a
+new feature prior to using automated tooling to perform the grunt work.
+
+Unguided use of those tools or the inability to prove understanding of
+the code contributed will result in a loss of trust in that contributor
+by project maintainers which can then lead to exclusion from any further
+contribution to the project.
+
+As with any other submissions, authors are responsible for doing due
+diligence and ensuring their submissions are compatible with the
+project's license as documented in LICENSES/README.md.
 
 ## Reviewing Pull Requests