[chore] Add commit-message guard (local hook + CI)

.githooks/commit-msg

@@ -0,0 +1,10 @@
+#!/bin/sh
+# Reject commit messages that credit an AI assistant (Claude/Anthropic) as co-author.
+# Shared with the team via core.hooksPath (.githooks), wired by the root "prepare" script.
+# Server-side CI (.github/workflows/guard-commit-messages.yml) is the bypass-proof backstop
+# for anyone who commits with --no-verify or without running `pnpm install`.
+if grep -qiE '^[[:space:]]*co-authored-by:.*(claude|anthropic)' "$1"; then
+  echo "✖ commit-msg: commit messages must not credit Claude/Anthropic as co-author." >&2
+  echo "  Remove the 'Co-Authored-By: ... claude/anthropic ...' line and try again." >&2
+  exit 1
+fi

.github/workflows/guard-commit-messages.yml

@@ -0,0 +1,23 @@
+name: Guard commit messages
+
+on:
+  pull_request:
+
+jobs:
+  no-ai-coauthors:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6.0.2
+        with:
+          fetch-depth: 0
+      - name: Reject AI co-author trailers
+        env:
+          BASE_REF: ${{ github.base_ref }}
+        run: |
+          git fetch origin "$BASE_REF" --depth=200
+          if git log "origin/$BASE_REF..HEAD" --format='%B' \
+             | grep -qiE '^[[:space:]]*co-authored-by:.*(claude|anthropic)'; then
+            echo "::error::A commit in this PR credits Claude/Anthropic as co-author. Remove the 'Co-Authored-By' trailer and force-update the branch."
+            exit 1
+          fi
+          echo "OK — no AI co-author trailers found."

package.json

@@ -2,7 +2,9 @@
   "name": "@org/source",
   "version": "0.0.0",
   "license": "MIT",
-  "scripts": {},
+  "scripts": {
+    "prepare": "git config core.hooksPath .githooks || true"
+  },
   "private": true,
   "dependencies": {
     "@angular-devkit/build-angular": "21.2.7",