Fix deprecated on:click

.github/copilot-instructions.md

@@ -62,7 +62,7 @@ Edit
 <div class="rounded-lg border border-gray-300 p-4 flex flex-col gap-4">
   <button
     class="rounded-md px-4 py-2 bg-blue-600 text-white"
-    on:click={() => count++}
+    onclick={() => count++}
     aria-label="Increment counter"
   >
     {count}