add new flag to disable some future features and make some updates to chat ux

frontend/src/routes/+page.svelte

@@ -1,5 +1,4 @@
 <script lang="ts">
-	import { onMount } from 'svelte';
 	import Footer from '$lib/components/Footer.svelte';
 	import FamDone from '$lib/components/FamDone.svelte';
 	import { homeIcon, checkCircleIcon, chevronRightIcon } from '$lib/components/icons';
@@ -8,7 +7,7 @@
 
 	let shortcut = $state<(Shortcut & { target: string }) | null>(null);
 
-	onMount(() => {
+	$effect(() => {
 		const s = readShortcut();
 		if (s) shortcut = { ...s, target: shortcutTarget(s) };
 	});