refactor: remove duplicate utils/utils.ts, consolidate into utils.ts

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/frontend/src/routes/admin/+layout.svelte

@@ -18,7 +18,7 @@
   <div class="container mx-auto px-4">
     <div class="flex min-h-screen">
       <!-- Sidebar -->
-      <aside class="w-56 shrink-0 border-r border-border/40 bg-card/60 backdrop-blur-sm flex flex-col">
+      <aside class="w-56 shrink-0 flex flex-col">
         <div class="px-4 py-5 border-b border-border/40">
           <a href="/" class="text-xs text-muted-foreground hover:text-foreground transition-colors">
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