refactor(frontend): use composition api

packages/frontend/src/pages/preview.vue

@@ -1,21 +0,0 @@
-<template>
-<div>
-	<MkSample/>
-</div>
-</template>
-
-<script lang="ts" setup>
-import { computed } from 'vue';
-import MkSample from '@/components/MkSample.vue';
-import { i18n } from '@/i18n';
-import { definePageMetadata } from '@/scripts/page-metadata';
-
-const headerActions = $computed(() => []);
-
-const headerTabs = $computed(() => []);
-
-definePageMetadata(computed(() => ({
-	title: i18n.ts.preview,
-	icon: 'ti ti-eye',
-})));
-</script>