feat(chat-web): add Docker deployment for chat frontend

- Add @sveltejs/adapter-node for server-side rendering
- Create Dockerfile for chat web SvelteKit app
- Add /health endpoint for container health checks
- Add chat-web service to docker-compose.staging.yml
- Update CI/CD workflow with chat-web health check

The chat app now deploys with both backend and web frontend:
- mana-core-auth (port 3001) - central auth
- chat-backend (port 3002) - API
- chat-web (port 3000) - web frontend

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.github/workflows/cd-staging.yml

@@ -21,6 +21,7 @@ on:
           - all
           - mana-core-auth
           - chat-backend
+          - chat-web
   workflow_call:
 
 permissions:
@@ -224,6 +225,17 @@ jobs:
               exit 1
             fi
 
+            # Check chat-web
+            echo "Checking chat-web..."
+            if docker compose exec -T chat-web wget -q -O - http://localhost:3000/health > /dev/null 2>&1; then
+              echo "✅ chat-web is healthy"
+            else
+              echo "❌ chat-web health check failed"
+              echo "=== Logs ==="
+              docker compose logs --tail=50 chat-web
+              exit 1
+            fi
+
             echo ""
             echo "✅ All health checks passed!"
           EOF