refactor: fix type errors

frontend/src/lib/components/ui/command/command-group.svelte

@@ -1,9 +1,10 @@
 <script lang="ts">
 	import { Command as CommandPrimitive } from "cmdk-sv";
 	import { cn } from "$lib/utils/style.js";
+	import type { ClassValue } from "svelte/elements";
 	type $$Props = CommandPrimitive.GroupProps;
 
-	let className: string | undefined | null = undefined;
+	let className: ClassValue | undefined | null = undefined;
 	export { className as class };
 </script>