Add npm publish GitHub Actions workflow

.github/workflows/npm-publish.yml

@@ -0,0 +1,37 @@
+name: Publish to npm
+
+on:
+  push:
+    tags:
+      - '[0-9]+.[0-9]+.[0-9]+'
+
+permissions:
+  contents: read
+  id-token: write
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Bun
+        uses: oven-sh/setup-bun@v2
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 24
+          registry-url: 'https://registry.npmjs.org'
+
+      - name: Verify tag matches package.json version
+        run: node -e "const {version}=require('./package.json'); const tag=process.env.GITHUB_REF_NAME; if(version!==tag){console.error(\`Tag \${tag} does not match package.json version \${version}\`); process.exit(1);}"
+
+      - name: Install dependencies
+        run: bun install --frozen-lockfile
+
+      - name: Publish
+        run: npm publish --provenance --access public
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}