feat: async file upload

src/lib/components/chat/Chat.svelte

@@ -90,6 +90,7 @@
 	import { fade } from 'svelte/transition';
 	import Tooltip from '../common/Tooltip.svelte';
 	import Sidebar from '../icons/Sidebar.svelte';
+	import { uploadFile } from '$lib/apis/files';
 
 	export let chatIdProp = '';