feat(ci): add skill release commit validation

Add CI check to ensure commits touching skills/<name>/** use
Conventional Commit subjects. Also validates SKILL.md version
alignment during publish/sync.

.github/workflows/test.yml

@@ -11,6 +11,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
 
       - name: Setup Node.js
         uses: actions/setup-node@v4
@@ -18,6 +20,9 @@ jobs:
           node-version: 22
           cache: npm
 
+      - name: Verify skill release commits
+        run: npm run verify:skill-release-commits
+
       - name: Install dependencies
         run: npm ci