Update guest v2 branding and theming

resources/js/guest-v2/components/AmbientBackground.tsx

@@ -1,14 +1,13 @@
 import React from 'react';
 import { YStack } from '@tamagui/stacks';
-import { useAppearance } from '@/hooks/use-appearance';
+import { useGuestThemeVariant } from '../lib/guestTheme';
 
 type AmbientBackgroundProps = {
   children: React.ReactNode;
 };
 
 export default function AmbientBackground({ children }: AmbientBackgroundProps) {
-  const { resolved } = useAppearance();
-  const isDark = resolved === 'dark';
+  const { isDark } = useGuestThemeVariant();
 
   return (
     <YStack