feat: improve SSR mobile detection

frontend_nuxt/utils/screen.js

@@ -1,18 +1,26 @@
 import { ref, computed } from 'vue'
+import { useRequestHeaders } from 'nuxt/app'
 
 const width = ref(0)
 const isClient = ref(false)
 
 // 检测移动设备的用户代理字符串
 const isMobileUserAgent = () => {
-  if (typeof navigator === 'undefined') return false
-  
-  const userAgent = navigator.userAgent.toLowerCase()
+  let userAgent = ''
+
+  if (typeof navigator !== 'undefined') {
+    userAgent = navigator.userAgent.toLowerCase()
+  } else {
+    // 服务端：从请求头获取用户代理字符串
+    const headers = useRequestHeaders(['user-agent'])
+    userAgent = (headers['user-agent'] || '').toLowerCase()
+  }
+
   const mobileKeywords = [
     'android', 'iphone', 'ipad', 'ipod', 'blackberry', 'windows phone',
     'mobile', 'tablet', 'opera mini', 'iemobile'
   ]
-  
+
   return mobileKeywords.some(keyword => userAgent.includes(keyword))
 }
 
@@ -30,8 +38,8 @@ export const isMobile = computed(() => {
   if (isClient.value) {
     // 客户端：优先使用窗口宽度，如果窗口宽度不可用则使用用户代理
     return width.value > 0 ? width.value <= 768 : isMobileUserAgent()
-  } else {
-    // 服务端：使用用户代理字符串
-    return isMobileUserAgent()
   }
+
+  // 服务端：使用请求头中的用户代理字符串
+  return isMobileUserAgent()
 })