chore: streamline the URL used for resources like favicon.png

src/lib/components/chat/Overview/Node.svelte

@@ -21,7 +21,7 @@
 		{#if data.message.role === 'user'}
 			<div class="flex w-full">
 				<ProfileImage
-					src={data.user?.profile_image_url ?? '/user.png'}
+					src={data.user?.profile_image_url ?? `${WEBUI_BASE_URL}/user.png`}
 					className={'size-5 -translate-y-[1px]'}
 				/>
 				<div class="ml-2">