fix: 修复主题无法保存的问题

src/App.vue

@@ -4,13 +4,13 @@ import Dialog from "./components/Dialog.vue";
 import { Alert, useAlertProvider } from "./components/Alert";
 import { ref, provide, computed, onMounted } from "vue";
 import { useRouter } from "vue-router";
+import { useThemeStore } from "./stores/theme";
 
 const router = useRouter();
+const theme = useThemeStore();
 
 // 主题切换状态管理
-const isDarkMode = ref(
-  window.matchMedia("(prefers-color-scheme: dark)").matches,
-);
+const isDarkMode = ref(theme.isDarkTheme());
 
 // Navbar显示状态管理
 const showNavbar = ref(true);
@@ -46,6 +46,7 @@ const applyTheme = () => {
 // 切换主题
 const toggleTheme = () => {
   isDarkMode.value = !isDarkMode.value;
+  theme.toggleTheme();
   applyTheme();
 };