feat: 重构 usePWAInstall 逻辑，优化 iOS 设备检测和安装提示处理

src/composables/usePWAInstall.ts

@@ -3,7 +3,7 @@ interface BeforeInstallPromptEvent extends Event {
   userChoice: Promise<{ outcome: "accepted" | "dismissed" }>;
 }
 
-export function usePWAInstall() {
+// 全局状态，在模块加载时就创建
 const deferredPrompt = ref<BeforeInstallPromptEvent | null>(null);
 const canInstall = ref(false);
 const isInstalled = ref(false);
@@ -18,24 +18,18 @@ export function usePWAInstall() {
   return isIOS() && !(window.navigator as any).standalone;
 }
 
-  // 使用 onMounted 确保在客户端环境执行
+// 在模块加载时就设置监听器（不等待组件挂载）
-  onMounted(() => {
+if (typeof window !== "undefined") {
-    console.log("[PWA] usePWAInstall mounted");
-
   // 检查是否已安装
   if (window.matchMedia("(display-mode: standalone)").matches) {
     isInstalled.value = true;
     console.log("[PWA] Already installed (standalone mode)");
-      return;
   }
-
+  else if ((window.navigator as any).standalone === true) {
-    // 检查 iOS Safari 独立模式
-    if ((window.navigator as any).standalone === true) {
     isInstalled.value = true;
     console.log("[PWA] Already installed (iOS standalone)");
-      return;
   }
-
+  else {
     // 监听安装提示事件（仅 Android/Chrome）
     window.addEventListener("beforeinstallprompt", (e: Event) => {
       console.log("[PWA] beforeinstallprompt event fired");
@@ -57,6 +51,14 @@ export function usePWAInstall() {
       console.log("[PWA] iOS Safari detected, showing install button");
       canInstall.value = true;
     }
+  }
+}
+
+export function usePWAInstall() {
+  onMounted(() => {
+    console.log("[PWA] usePWAInstall mounted");
+    console.log("[PWA] canInstall:", canInstall.value);
+    console.log("[PWA] isInstalled:", isInstalled.value);
   });
 
   async function install() {