ci: add the e2e-verdaccio skeleton as a GitHub action

.github/verdaccio/com.example.demo/package.json

@@ -0,0 +1,4 @@
+{
+  "name": "com.example.demo",
+  "version": "1.0.0"
+}

.github/workflows/e2e-verdaccio.yml

@@ -0,0 +1,28 @@
+name: verdaccio e2e demo
+
+on: push
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    name: setup verdaccio
+    services:
+      verdaccio:
+        image: verdaccio/verdaccio:5
+        ports:
+          - 4873:4873
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: Setup Node.js
+      uses: actions/setup-node@v4
+      with:
+        node-version: "22.x"
+    - name: login
+      run: npx npm-cli-login -u tester -p 123456 -e tester@example.com -r http://localhost:4873
+    - name: publish
+      run: npm publish --registry http://localhost:4873
+      working-directory: .github/verdaccio/com.example.demo
+    - name: check
+      run: npm info com.example.demo --json --registry http://localhost:4873
+      working-directory: .github/verdaccio/com.example.demo