fix: hide file preview while loading

src/lib/components/chat/ChatWindow.svelte

@@ -342,7 +342,7 @@
 	<div
 		class="dark:via-gray-80 pointer-events-none absolute inset-x-0 bottom-0 z-0 mx-auto flex w-full max-w-3xl flex-col items-center justify-center bg-gradient-to-t from-white via-white/80 to-white/0 px-3.5 py-4 dark:border-gray-800 dark:from-gray-900 dark:to-gray-900/0 max-md:border-t max-md:bg-white max-md:dark:bg-gray-900 sm:px-5 md:py-8 xl:max-w-4xl [&>*]:pointer-events-auto"
 	>
-		{#if sources?.length}
+		{#if sources?.length && !loading}
 			<div class="flex flex-row flex-wrap justify-center gap-2.5 max-md:pb-3">
 				{#each sources as source, index}
 					{#await source then src}