feat(ux): implement UX audit recommendations

- Redesign landing page with unified Omnibox search

- Add ComparisonToast for better comparison flow visibility

- Add visual 'Added' state to SchoolCard

- Add info tooltips to educational metrics

- Optimize mobile map view with Bottom Sheet

- Standardize distance display to miles

nextjs-app/app/layout.tsx

@@ -3,6 +3,7 @@ import { DM_Sans, Playfair_Display } from 'next/font/google';
 import Script from 'next/script';
 import { Navigation } from '@/components/Navigation';
 import { Footer } from '@/components/Footer';
+import { ComparisonToast } from '@/components/ComparisonToast';
 import { ComparisonProvider } from '@/context/ComparisonProvider';
 import './globals.css';
 
@@ -70,6 +71,7 @@ export default function RootLayout({
           <main className="main">
             {children}
           </main>
+          <ComparisonToast />
           <Footer />
         </ComparisonProvider>
       </body>