feat: replace clsx with cn util

src/shared/lib/storybook/MockIcon.svelte

@@ -7,7 +7,7 @@
     correctly via the HTML element's class attribute.
 -->
 <script lang="ts">
-import clsx from 'clsx';
+import { cn } from '$shared/lib';
 import type {
     Component,
     Snippet,
@@ -32,7 +32,7 @@ let { icon: Icon, class: className, attrs = {} }: Props = $props();
 </script>
 
 {#if Icon}
-    {@const __iconClass__ = clsx('size-4', className)}
+    {@const __iconClass__ = cn('size-4', className)}
     <!-- Render icon component dynamically with class prop -->
     <Icon
         class={__iconClass__}