ci: add GitHub Actions workflow for npm publish

.github/workflows/publish.yml

@@ -0,0 +1,46 @@
+name: Publish to npm
+
+on:
+  push:
+    branches:
+      - lantanios
+  workflow_dispatch:
+
+jobs:
+  build-and-publish:
+    runs-on: ubuntu-latest
+    
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+          registry-url: 'https://registry.npmjs.org'
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 10
+
+      - name: Install dependencies
+        run: pnpm install
+
+      - name: Build
+        run: pnpm build
+
+      - name: Update package name for scoped publish
+        run: |
+          node -e "
+            const fs = require('fs');
+            const pkg = JSON.parse(fs.readFileSync('package.json', 'utf8'));
+            pkg.name = '@lantanios/moltbot';
+            fs.writeFileSync('package.json', JSON.stringify(pkg, null, 2));
+          "
+
+      - name: Publish to npm
+        run: npm publish --access public
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}