Add GitHub Actions workflow for frontend deployment to Vercel

Set up automated deployment pipeline that triggers on pull requests
to develop branch when client/ directory changes. Includes Node.js 20
setup, yarn dependency installation, build process, and Vercel deployment.

Author: LiusCraft

.github/workflows/deploy-frontend.yml

@@ -0,0 +1,57 @@
+name: Deploy Frontend to Vercel
+
+on:
+  pull_request:
+    branches: [develop]
+    paths: ['client/**']
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: write
+    
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+      
+    - name: Setup Node.js
+      uses: actions/setup-node@v4
+      with:
+        node-version: '20'
+        cache: 'yarn'
+        cache-dependency-path: client/yarn.lock
+        
+    - name: Install dependencies
+      run: |
+        cd client
+        yarn install --frozen-lockfile
+        
+    - name: Build project
+      run: |
+        cd client
+        yarn build
+        
+    - name: Deploy to Vercel
+      id: vercel-deploy
+      uses: amondnet/vercel-action@v25
+      with:
+        vercel-token: ${{ secrets.VERCEL_TOKEN }}
+        vercel-org-id: ${{ secrets.VERCEL_ORG_ID }}
+        vercel-project-id: ${{ secrets.VERCEL_PROJECT_ID }}
+        working-directory: ./client
+        scope: ${{ secrets.VERCEL_ORG_ID }}
+        
+    - name: Comment PR
+      if: github.event_name == 'pull_request'
+      uses: actions/github-script@v7
+      with:
+        script: |
+          const deployUrl = '${{ steps.vercel-deploy.outputs.preview-url }}';
+          github.rest.issues.createComment({
+            issue_number: context.issue.number,
+            owner: context.repo.owner,
+            repo: context.repo.repo,
+            body: `🚀 **Frontend deployed successfully!**\n\n📱 **Preview URL:** ${deployUrl || 'Deployment in progress...'}\n\n✅ Build completed successfully`
+          });

.gitignore

@@ -313,3 +313,4 @@ __debug_bin
 .dockerignore
 
 CLAUDE.md
+.vercel