feat: add Docker deployment configuration

- Add server Dockerfile with multi-stage build
- Add frontend Dockerfile with Nginx
- Add docker-compose.yml for orchestration
- Add Nginx config with SSL support
- Add deployment documentation

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

.env.production

@@ -0,0 +1,14 @@
+# 生产环境配置
+NODE_ENV=production
+
+# 服务端口
+PORT=3000
+
+# Redis 连接
+REDIS_URL=redis://redis:6379
+
+# CORS 允许的域名（多个用逗号分隔）
+CORS_ORIGINS=https://your-domain.com,https://www.your-domain.com
+
+# 你的域名（用于生成二维码等）
+DOMAIN=your-domain.com