Add publish workflow and minimal npm package for WASM

.github/workflows/publish-wasm.yml

@@ -0,0 +1,69 @@
+name: publish-wasm
+
+on:
+  push:
+    tags:
+      - '[0-9]*.[0-9]*.[0-9]*'
+
+jobs:
+  publish:
+    name: Publish MuJoCo WASM package
+    runs-on: ubuntu-24.04
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Setup Node.js for WASM bindings
+      uses: actions/setup-node@v4
+      with:
+        node-version: '20'
+
+    - name: Prepare Linux
+      run: bash ./.github/workflows/build_steps.sh prepare_linux
+
+    - name: Install NPM Dependencies for WASM bindings
+      run: bash ./.github/workflows/build_steps.sh npm_ci
+
+    - name: Setup Emscripten for WASM bindings
+      run: bash ./.github/workflows/build_steps.sh setup_emsdk
+
+    - name: Build WASM bindings
+      run: bash ./.github/workflows/build_steps.sh build_test_wasm
+
+    - name: Prepare clean package manifest in dist
+      run: |
+        if [ -f wasm/package.npm.json ]; then
+          mkdir -p wasm/dist
+          cp wasm/package.npm.json wasm/dist/package.json
+          echo "Copied wasm/package.npm.json -> wasm/dist/package.json"
+        else
+          echo "No wasm/package.npm.json found; aborting"
+          exit 1
+        fi
+
+    - name: Prepare README for dist
+      run: |
+        if [ -f wasm/README.npm.md ]; then
+          mkdir -p wasm/dist
+          cp wasm/README.npm.md wasm/dist/README.md
+          echo "Copied wasm/README.npm.md -> wasm/dist/README.md"
+        else
+          echo "No wasm/README.npm.md found; skipping README copy"
+        fi
+
+    - name: Sync version with tag (dist)
+      run: |
+        VERSION=${GITHUB_REF#refs/tags/}
+        echo "Setting package version to: ${VERSION}"
+        npm --prefix wasm/dist version "${VERSION}" --no-git-tag-version
+
+    - name: Configure npm auth
+      env:
+        NPM_TOKEN: ${{ secrets.NPM_ACCESS_TOKEN }}
+      run: |
+        echo "//registry.npmjs.org/:_authToken=${NPM_TOKEN}" > ~/.npmrc
+
+    - name: Preview package (dist)
+      run: npm pack --dry-run ./wasm/dist
+
+    - name: Publish package (dist)
+      run: npm publish ./wasm/dist --access public