diff --git a/AGENTS.md b/AGENTS.md
index 46d257a..b49cf54 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -73,10 +73,10 @@ Guide for LLM-based assistants (Codex/Copilot/ChatGPT, etc.) working in this rep
 
 **Git flow (no ad-hoc diffs):**
 
-* Branch naming for issue-tied work: `GH-<issue number>`, nothing appended.
-* Commit subjects start with a capitalised imperative verb and carry a `GH-<issue number>: ` prefix
-  when the commit belongs to an issue (`GH-55: Reject an enum value that does not match the backing
-  type`). No `feat:`/`fix:`/`chore:` prefixes.
+- Commit subjects — and the pull-request title — are governed by the shared `commit-convention` gate; the normative rule and its full rationale live in `magicsunday/.github/.github/workflows/commit-convention.yml@main`, which self-tests a decision table before applying it. In short: a `GH-`-prefixed subject must match `^GH-\d+: [A-Z]`, every other subject `^[A-Z]` — a capitalised English imperative — and conventional-commit prefixes (`feat:`, `Fix:`, …) as well as path-like starts (`src/…: …`) are rejected whatever their case. It runs on every pull request via `.github/workflows/commit-lint.yml`, advisory until `commit-convention / Commit convention` is a required context in branch protection.
+- Branches for an issue are named exactly `GH-<N>`; the `GH-<N>: ` prefix marks work that belongs to that issue, so a drive-by fix on the branch keeps its own unprefixed subject.
+- The pull-request body closes the issue with `Closes #<N>` — the `GH-<N>: ` subject prefix is not a GitHub link and closes nothing.
+- Never add a `Co-Authored-By:` trailer or any other AI attribution.
 * One concern per commit; keep formatting-only changes out of a behavioural commit.
 * Open PRs early, keep CI green, assign reviewers.
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 06e06bc..10e4a91 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -27,8 +27,11 @@ CI at ≥ 90 %; run it locally with `composer ci:test:php:coverage:gate`.
 ## Commits and pull requests
 
 - Branch from `main`. Name an issue-tied branch exactly `GH-<number>`.
-- Commit subjects are English, imperative, and capitalised: `GH-<number>: Add …` for issue-tied
-  work, or `Add …` for a free change. No `feat:`/`fix:` conventional-commit prefixes.
+- Commit subjects — and the pull-request title — are governed by the shared
+  `commit-convention` gate; the normative rule lives in
+  `magicsunday/.github/.github/workflows/commit-convention.yml@main` and is summarised in
+  [`AGENTS.md`](AGENTS.md). In short: `GH-<number>: Add …` for issue-tied work, or `Add …`
+  for a free change — a capitalised English imperative, no `feat:`/`fix:` prefixes.
 - Group changes into logical commits — one concern each; keep style-only fixes separate from
   behaviour changes.
 - Open the PR against `main`, describe the scope, the motivation, and how you verified it, and close