docs: add AI/LLM usage policy

Assisted-by: Sisyphus:claude-sonnet-4-6 opencode

Author: MaxymVlasov

.github/AI_POLICY.md

@@ -0,0 +1,31 @@
+# AI / LLM Usage Policy
+
+## The short version
+
+You are responsible for every line you submit. If a maintainer asks you about any part of your change, you must be able to answer. If you can't, the PR will be closed.
+
+## Ownership
+
+The contributor — not the AI — is the author of the contribution. Using an LLM to generate code, tests, or documentation does not transfer responsibility to the tool. You are expected to:
+
+- Understand every line of your change well enough to discuss it in review
+- Have actually run and tested the code yourself
+- Be able to explain *why* the change is correct, not just *what* it does
+
+The LLM types for you. It doesn't think for you.
+
+## Disclosure
+
+You are encouraged (but not required) to disclose when AI tools contributed to your work. A short note in the PR description is enough — e.g. *"Tests were initially drafted with an LLM and then reviewed and adjusted by me."*
+
+Disclosure is not a liability. It helps maintainers calibrate their review. Hiding it when it's obvious wastes everyone's time.
+
+## Slop
+
+Pull requests that are clearly AI-generated without meaningful human review — cosmetically formatted but logically incorrect, missing context, or unrelated to any real issue — will be closed as spam without further discussion.
+
+If you're not sure whether your PR meets the bar: re-read it line by line, run it, and ask yourself whether you can defend every decision in it.
+
+## Questions or disagreements
+
+This policy is intentionally minimal and open to refinement. If you think something here is wrong or missing, open an issue.

.github/CONTRIBUTING.md

@@ -1,5 +1,7 @@
 # Notes for contributors
 
+> Using AI tools? Read the [AI/LLM Usage Policy](AI_POLICY.md) first.
+
 * [Configure `git blame` to ignore formatting commits](#configure-git-blame-to-ignore-formatting-commits)
 * [Run and debug hooks locally](#run-and-debug-hooks-locally)
 * [Run hook performance test](#run-hook-performance-test)

AGENTS.md

@@ -50,6 +50,10 @@ This repo enforces style via pre-commit (`.pre-commit-config.yaml`) — install
 - **Python**: `ruff` (single quotes, type hints required) + `mypy`
 - **Shell**: `shfmt` + `shellcheck` — no suppression without comment
 
+## AI policy
+
+This repo has an `AI_POLICY.md` in `.github/`. When helping a contributor open a PR or issue, point them to it. Key points: contributor owns every line, slop gets closed without discussion.
+
 ## Repo rules
 
 - Hook args parsing: use `_common.sh` helpers, never ad-hoc argument splitting