Add Docker-based production deployment

- Multi-stage Dockerfile with Node builder and nginx server
- Nginx configuration with gzip, security headers, and caching
- Docker Compose setup with health checks
- Updated README with deployment instructions

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

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Dockerfile

@@ -0,0 +1,37 @@
+# Multi-stage build for production deployment
+
+# Stage 1: Build the application
+FROM node:20-alpine AS builder
+
+WORKDIR /app
+
+# Copy package files
+COPY package*.json ./
+
+# Install dependencies
+RUN npm ci --only=production
+
+# Copy source code
+COPY . .
+
+# Build the application
+RUN npm run build
+
+# Stage 2: Serve with nginx
+FROM nginx:alpine
+
+# Copy built files from builder stage
+COPY --from=builder /app/dist /usr/share/nginx/html
+
+# Copy nginx configuration
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+
+# Expose port 80
+EXPOSE 80
+
+# Health check
+HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
+  CMD wget --quiet --tries=1 --spider http://localhost/ || exit 1
+
+# Start nginx
+CMD ["nginx", "-g", "daemon off;"]