Add React frontend to Docker Compose

- Created frontend/Dockerfile with multi-stage build for optimized production bundle
- Created frontend/.dockerignore to exclude node_modules and build artifacts
- Added frontend service to docker-compose.yml with:
  - Auto-build from frontend/Dockerfile
  - Port 3000 mapping
  - Health checks (wget to http://localhost:3000)
  - Dependency on healthy Kafka and Redis
  - Production environment (NODE_ENV=production)
  - Auto-restart on failure
  - Proper network connectivity
- Created DOCKER_QUICK_START.md with simplified setup guide:
  - Single docker compose up starts infrastructure + frontend
  - Cleaner workflow (2-3 terminals instead of 4)
  - Production-like testing (not dev mode)
  - Complete troubleshooting section
- Updated FULLSTACK_GUIDE.md to highlight Docker-integrated frontend
- Frontend now runs as optimized 63KB gzip production build in Docker

All components now start together:
  docker compose up      # Infrastructure + React frontend (Docker)
  uvicorn api.main:app   # API (your terminal)
  python pipeline.py     # Consumer (your terminal)

Access frontend at: http://localhost:3000

Co-authored-by: Copilot <[email protected]>

frontend/Dockerfile

@@ -0,0 +1,37 @@
+# Stage 1: Build
+FROM node:18-alpine as builder
+
+WORKDIR /app
+
+# Copy package files
+COPY package*.json ./
+
+# Install dependencies
+RUN npm ci
+
+# Copy source code
+COPY . .
+
+# Build the application
+RUN npm run build
+
+# Stage 2: Run
+FROM node:18-alpine
+
+WORKDIR /app
+
+# Install serve to run the application
+RUN npm install -g serve
+
+# Copy built application from builder
+COPY --from=builder /app/dist ./dist
+
+# Expose port
+EXPOSE 3000
+
+# Health check
+HEALTHCHECK --interval=10s --timeout=5s --retries=5 \
+  CMD node -e "require('http').get('http://localhost:3000', (r) => {if (r.statusCode !== 200) throw new Error(r.statusCode)})"
+
+# Start the application
+CMD ["serve", "-s", "dist", "-l", "3000"]