ci: add npm publish workflow

Triggered by version tags (v*) or manual dispatch.
Uses NPM_TOKEN secret for authentication.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: zenabot27

.github/workflows/publish.yml

@@ -0,0 +1,37 @@
+name: Publish to npm
+
+on:
+  push:
+    tags:
+      - 'v*'
+  workflow_dispatch:
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          registry-url: 'https://registry.npmjs.org'
+
+      - name: Install dependencies
+        run: bun install --frozen-lockfile
+
+      - name: Build
+        run: |
+          bun run build
+          bun run build:http
+
+      - name: Publish
+        run: npm publish --access public
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}