修复 Drone CI 配置：移除 host volumes 以解决 untrusted 仓库问题

- 移除 npm-cache volume 挂载
- 同一构建内的步骤仍可共享 node_modules
- 使用国内镜像加速依赖下载

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

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

.drone.yml

@@ -13,9 +13,6 @@ steps:
   # 步骤1：安装依赖
   - name: 安装依赖
     image: node:18-alpine
-    volumes:
-      - name: npm-cache
-        path: /root/.npm
     commands:
       - echo "开始安装 npm 依赖..."
       - npm install --registry=https://registry.npmmirror.com
@@ -63,9 +60,3 @@ steps:
       - sleep 5
       - curl -f http://154.30.6.21:2888 || exit 1
       - echo "✅ 前端访问正常"
-
-# 挂载卷（缓存 npm 依赖）
-volumes:
-  - name: npm-cache
-    host:
-      path: /data/drone-cache/npm