feat: 移除未使用的导入，优化代码结构

src/main.ts

@@ -1,5 +1,3 @@
-import type { WritableComputedRef } from "vue";
-import type { Locale } from "vue-i18n";
 import { IonicVue } from "@ionic/vue";
 import { createPinia } from "pinia";
 import { createApp } from "vue";
@@ -39,6 +37,8 @@ import "./theme/index.css";
 import "./theme/variables.css";
 import "./theme/ionic.css";
 
+useTheme();
+
 const pinia = createPinia();
 
 const app = createApp(App)

src/views/system-settings/theme.vue

@@ -1,6 +1,5 @@
 <script lang="ts" setup>
 import type { ThemeMode } from "@/composables/useTheme";
-import { useIonRouter } from "@ionic/vue";
 
 const { t } = useI18n();
 const { theme } = useTheme();