docs: ai policy

Signed-off-by: Jan Larwig <jan@larwig.com>

CONTRIBUTING.md

@@ -21,3 +21,25 @@ If you find a bug, please open an Issue.
 If you want to fix a bug, please fork, create a feature branch, fix the bug and
 open a PR back to this repo.
 Please mention the open bug issue number within your PR if applicable.
+
+## AI use
+
+OAuth2 Proxy is built by humans for humans. Authentication and authorization
+depend on trust between people and systems. That trust also matters in how we
+work together.
+
+You may use AI tools when contributing, but YOU must not replace human
+communication or judgment using those tools. You must understand, test, and 
+review every AI-assisted change yourself. Write a clear, concise pull request 
+description and respond to review comments yourself.
+
+Listing AI tooling as a co-author, co-signing commits using an AI tool, or 
+using the `assisted-by`, `co-developed` or similar commit trailer is not allowed.
+
+The project maintainers will review contributions regardless of their origin. 
+But we may close issues or pull requests without comment when they appear to be 
+unreviewed automated output, low-quality slop, or contain essay-length descriptions 
+or comments that waste reviewer time.
+
+If a contribution does not show the care needed for a high-quality change,
+maintainers will not spend time reviewing it.