feat: 添加 Docker 部署配置

- 添加 Dockerfile (多阶段构建: Node 构建 → Nginx 托管)
- 添加 docker-compose.yml (端口 8801, 自动重启)
- 添加 .dockerignore (减少构建体积)
- 添加 docker-deploy.md (部署文档)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -0,0 +1,23 @@
+version: '3.8'
+
+services:
+  web:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    container_name: tianxuan-company
+    ports:
+      - "8801:80"
+    restart: unless-stopped
+    healthcheck:
+      test: ["CMD", "wget", "-q", "--spider", "http://localhost/"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 10s
+    networks:
+      - tianxuan-network
+
+networks:
+  tianxuan-network:
+    driver: bridge