fix: 修复特色图预览链接路径解析问题并添加 external 属性

src/lib/components/admin/FeaturedImagePicker.svelte

@@ -1,7 +1,6 @@
 <script lang="ts">
 	/* eslint-disable @typescript-eslint/no-explicit-any */
 
-	import { resolve } from '$app/paths';
 	import { addToast } from '$lib/stores/toast.svelte';
 	import { onMount } from 'svelte';
 	import Tabs from './Tabs.svelte';
@@ -141,7 +140,8 @@
 			{#if previewable}
 				<a
 					class="cover-preview-link"
-					href={resolve(cover)}
+					href={cover}
+					rel="external"
 					data-fancybox="featured-image-preview"
 					data-caption={title || '特色图'}
 					aria-label="查看特色图大图"