ci: update cosign to v2.4.0 and add semantic commit validation (#69)

.github/workflows/commitlint.yml

@@ -0,0 +1,40 @@
+---
+# yaml-language-server: $schema=https://json.schemastore.org/github-workflow.json
+name: Commit Messages
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+  push:
+    branches:
+      - main
+
+permissions:
+  contents: read
+
+jobs:
+  commitlint:
+    name: Validate Commit Messages
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          fetch-depth: 0
+
+      - name: Setup Node.js
+        uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5.0.0
+        with:
+          node-version: '22'
+
+      - name: Install commitlint
+        run: |
+          npm install --save-dev @commitlint/cli@19.6.1 @commitlint/config-conventional@19.6.0
+
+      - name: Validate current commit (for single commits)
+        if: github.event_name == 'push'
+        run: npx commitlint --from HEAD~1 --to HEAD --verbose
+
+      - name: Validate PR commits
+        if: github.event_name == 'pull_request'
+        run: npx commitlint --from ${{ github.event.pull_request.base.sha }} --to ${{ github.event.pull_request.head.sha }} --verbose