[Copilot]

The publish job failed with Unknown command: "stage". The job already pinned Node 22.22.2, which meets the 22.14.0 minimum. Node 22 bundles npm 10, and npm stage only exists from npm 11.15.0.

Changes (.github/workflows/npm-publish.yml, publish-npm job)

• Upgrade npm: a new step runs npm install -g npm@^11.15.0 right after setup-node, before npm ci and the publish.
• Verify before publish: a new step runs node -v, npm -v and npm help stage. A missing stage command now fails here with the versions in the log, not at publish time.

- name: Install npm with stage support
  run: npm install -g npm@^11.15.0
- name: Verify Node/npm support for stage
  run: |
    node -v
    npm -v
    npm help stage

Registry URL, NODE_AUTH_TOKEN, triggers, permissions and the build job are unchanged. I kept node-version: 22.22.2 rather than lowering it to 22.14.0.

The workflow has not been run yet, so the fix is unconfirmed until a publish run exercises it.