ci: build and publish MCPB bundle for pdf-server (#495)

- Add *.mcpb to .gitignore (built artifacts)
- Validate MCPB pack in CI (Linux x64 only)
- Build and upload .mcpb as GitHub release asset on publish

.github/workflows/npm-publish.yml

@@ -138,3 +138,35 @@ jobs:
         run: npm publish --workspace examples/${{ matrix.example }} --provenance --access public
         env:
           NODE_AUTH_TOKEN: ${{ secrets.NPM_SECRET }}
+
+  publish-mcpb:
+    runs-on: ubuntu-latest
+    if: github.event_name == 'release'
+    environment: Release
+    needs: [publish-examples]
+
+    permissions:
+      contents: write
+
+    steps:
+      - uses: actions/checkout@v6
+      - uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+      - uses: actions/setup-node@v6
+        with:
+          node-version: "22"
+          cache: npm
+      - run: npm ci
+
+      - name: Build pdf-server
+        run: npm run build --workspace examples/pdf-server
+
+      - name: Pack MCPB bundle
+        run: npx -y @anthropic-ai/mcpb pack
+        working-directory: examples/pdf-server
+
+      - name: Upload MCPB to release
+        run: gh release upload "${{ github.event.release.tag_name }}" examples/pdf-server/*.mcpb --clobber
+        env:
+          GH_TOKEN: ${{ github.token }}