ci: reject PRs that reference the assistant by name in title/body/commits

Server-side counterpart to the global commit-msg hook (which blocks the same word
locally, but can be bypassed with --no-verify or via GitHub UI edits). Checks only
message text, never file contents.

.github/workflows/no-claude.yml

@@ -0,0 +1,41 @@
+name: No Claude references
+
+# Server-side counterpart to the global commit-msg hook: rejects a PR whose
+# title, body, or commit messages mention "claude" (any case). Catches commits
+# pushed with --no-verify and edits made in the GitHub UI. Only message text is
+# checked — never file contents, since the code legitimately references claude.
+
+on:
+  pull_request:
+    types: [opened, edited, reopened, synchronize]
+
+permissions:
+  contents: read
+
+jobs:
+  no-claude:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check PR title and body
+        env:
+          TITLE: ${{ github.event.pull_request.title }}
+          BODY: ${{ github.event.pull_request.body }}
+        run: |
+          if printf '%s\n%s' "$TITLE" "$BODY" | grep -qi 'claude'; then
+            echo "::error::PR title or body mentions 'claude' — please remove it."
+            exit 1
+          fi
+
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Check commit messages
+        env:
+          BASE_SHA: ${{ github.event.pull_request.base.sha }}
+          HEAD_SHA: ${{ github.event.pull_request.head.sha }}
+        run: |
+          if git log --format='%B' "$BASE_SHA..$HEAD_SHA" | grep -qi 'claude'; then
+            echo "::error::A commit message in this PR mentions 'claude'."
+            exit 1
+          fi