feat: 集成 Cloudflare Tunnel 支持

- docker-compose.yml 添加 cloudflared 服务
- 更新 .env.example 和 README.md 添加配置说明
- 支持通过 Cloudflare Tunnel 进行安全部署

docker-compose.yml

@@ -29,3 +29,15 @@ services:
       timeout: 10s
       retries: 3
       start_period: 40s
+
+  # Cloudflare Tunnel (可选)
+  # 需要在 .env 中设置 TUNNEL_TOKEN
+  tunnel:
+    image: cloudflare/cloudflared:latest
+    container_name: droid2api_tunnel
+    restart: unless-stopped
+    command: tunnel run
+    environment:
+      - TUNNEL_TOKEN=${TUNNEL_TOKEN}
+    depends_on:
+      - droid2api