OPFS에 캐시된 썸네일을 모두 삭제하는 기능 추가

src/lib/components/atoms/divs/FullscreenDiv.svelte

@@ -1,7 +1,15 @@
 <script lang="ts">
-  let { children } = $props();
+  import type { Snippet } from "svelte";
+  import type { ClassValue } from "svelte/elements";
+
+  interface Props {
+    children: Snippet;
+    class?: ClassValue;
+  }
+
+  let { children, class: className }: Props = $props();
 </script>
 
-<div class="flex flex-grow flex-col justify-between px-4">
+<div class={["flex flex-grow flex-col justify-between px-4", className]}>
   {@render children()}
 </div>