ci: add PR validation check for type label or Conventional Commits title

.github/workflows/validate-pr.yml

@@ -0,0 +1,58 @@
+name: Validate PR
+
+on:
+    pull_request:
+        types: [opened, edited, synchronize, labeled, unlabeled]
+
+jobs:
+    validate:
+        runs-on: ubuntu-latest
+        permissions:
+            pull-requests: read
+        steps:
+            - name: Ensure PR has a valid type
+              uses: actions/github-script@v7
+              with:
+                  script: |
+                      const title = context.payload.pull_request.title;
+                      const prefixMatch = title.match(/^(\w+)(?:\([^)]*\))?(!)?:/);
+                      const prefix = prefixMatch?.[1]?.toLowerCase();
+
+                      const validPrefixes = [
+                          'feat', 'fix', 'perf', 'test', 'docs',
+                          'build', 'ci', 'refactor', 'task', 'chore', 'style',
+                      ];
+
+                      const hasValidPrefix = validPrefixes.includes(prefix);
+
+                      const { data: labels } = await github.rest.issues.listLabelsOnIssue({
+                          owner: context.repo.owner,
+                          repo: context.repo.repo,
+                          issue_number: context.payload.pull_request.number,
+                      });
+
+                      const typeLabels = [
+                          '[Type] Enhancement',
+                          '[Type] Bug',
+                          '[Type] Performance',
+                          '[Type] Automated Testing',
+                          '[Type] Developer Documentation',
+                          '[Type] Build Tooling',
+                          '[Type] Task',
+                          '[Type] Breaking Change',
+                          '[Type] Regression',
+                      ];
+
+                      const hasTypeLabel = labels.some((l) => typeLabels.includes(l.name));
+
+                      if (hasValidPrefix || hasTypeLabel) {
+                          const method = hasValidPrefix ? 'Conventional Commits prefix' : 'type label';
+                          core.info(`✅ PR has a valid type via ${method}`);
+                          return;
+                      }
+
+                      core.setFailed(
+                          'PR must have either a Conventional Commits title prefix (e.g. feat:, fix:, docs:) ' +
+                          'or a [Type] label applied manually.\n\n' +
+                          'See docs/code/developer-workflows.md for details.'
+                      );