chore: 添加百度站长平台验证文件 + build 脚本复制 .env

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

package.json

@@ -5,7 +5,7 @@
   "description": "呼籁旅行官网 - 呼伦贝尔家庭定制游",
   "scripts": {
     "dev": "nuxt dev",
-    "build": "nuxt build",
+    "build": "nuxt build && cp -f .env .output/.env 2>/dev/null || true",
     "generate": "nuxt generate",
     "preview": "nuxt preview"
   },

public/baidu_verify_codeva-EDkrGNKD97.html

@@ -0,0 +1 @@
+564d8b5b3aa83763be08eafc306e9d2c