cd: Add workflow for deploying react frontend to S3

.github/workflows/cd_react_frontend.yml

@@ -0,0 +1,41 @@
+name: CD deploy to S3
+
+on:
+  push:
+    branches:
+      - 'release/v[0-9]+.[0-9]+'
+
+jobs:
+  build-and-deploy:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+
+    - name: Set up Node.js
+      uses: actions/setup-node@v4
+      with:
+        node-version: '20.11.1'
+
+    - name: Install dependencies
+      working-directory: ./react_frontend
+      run: npm install
+
+    - name: Set environment variables
+      run: echo "REACT_APP_API_URL=${{ secrets.REACT_APP_API_URL }}" >> $GITHUB_ENV
+
+    - name: Build React app
+      working-directory: ./react_frontend
+      run: npm run build
+
+    - name: Deploy to S3
+      uses: jakejarvis/s3-sync-action@master
+      with:
+        args: --acl public-read --follow-symlinks --delete
+      env:
+        AWS_S3_BUCKET: ${{ secrets.AWS_S3_BUCKET }}
+        AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
+        AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
+        AWS_REGION: 'ap-southeast-1'
+        SOURCE_DIR: './react_frontend/build'