Add PR title linter to enforce Conventional Commits

release-please uses conventional commit messages to determine version
bumps. This workflow validates PR titles follow the format so squash
merges produce correct commit messages.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: gjtorikian

.github/workflows/lint-pr-title.yml

@@ -0,0 +1,20 @@
+name: Lint PR Title
+
+on:
+  pull_request_target:
+    types:
+      - opened
+      - edited
+      - synchronize
+
+permissions:
+  pull-requests: read
+
+jobs:
+  main:
+    name: Validate PR title
+    runs-on: ubuntu-latest
+    steps:
+      - uses: amannn/action-semantic-pull-request@v5
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}