ci: add automatic NPM publishing workflow (#1)

- Publishes to NPM when version changes in package.json
- Creates GitHub releases automatically
- Skips publishing for doc-only changes
- Free for public repositories

Author: nagasaicharan

.github/workflows/publish.yml

@@ -0,0 +1,62 @@
+name: Publish to NPM
+
+on:
+  push:
+    branches:
+      - main
+    paths-ignore:
+      - '**.md'
+      - 'example/**'
+      - 'assets/**'
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '18'
+          registry-url: 'https://registry.npmjs.org'
+          
+      - name: Install dependencies
+        run: yarn install --frozen-lockfile
+        
+      - name: Build package
+        run: yarn prepare
+        
+      - name: Check if version changed
+        id: version_check
+        run: |
+          CURRENT_VERSION=$(node -p "require('./package.json').version")
+          PUBLISHED_VERSION=$(npm view react-native-store-age-signals-native-modules version 2>/dev/null || echo "0.0.0")
+          echo "current=$CURRENT_VERSION" >> $GITHUB_OUTPUT
+          echo "published=$PUBLISHED_VERSION" >> $GITHUB_OUTPUT
+          if [ "$CURRENT_VERSION" != "$PUBLISHED_VERSION" ]; then
+            echo "changed=true" >> $GITHUB_OUTPUT
+          else
+            echo "changed=false" >> $GITHUB_OUTPUT
+          fi
+          
+      - name: Publish to NPM
+        if: steps.version_check.outputs.changed == 'true'
+        run: npm publish --access public
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
+          
+      - name: Create GitHub Release
+        if: steps.version_check.outputs.changed == 'true'
+        uses: actions/create-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: v${{ steps.version_check.outputs.current }}
+          release_name: Release v${{ steps.version_check.outputs.current }}
+          draft: false
+          prerelease: false