feat(01-05): update home page with auth-aware redirect

- Redirect authenticated users to dashboard
- Show landing page with value proposition for visitors
- Add clear CTAs for register and login
- Italian copy reflecting core product value

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/app/page.tsx

@@ -1,8 +1,47 @@
-export default function Home() {
+import { createClient } from '@/lib/supabase/server'
+import { redirect } from 'next/navigation'
+import Link from 'next/link'
+import { Button } from '@/components/ui/button'
+
+export default async function Home() {
+  const supabase = await createClient()
+  const { data: { user } } = await supabase.auth.getUser()
+
+  // If logged in, redirect to dashboard
+  if (user) {
+    redirect('/dashboard')
+  }
+
+  // Landing page for non-authenticated users
   return (
-    <main className="flex min-h-screen flex-col items-center justify-center p-24">
-      <h1 className="text-4xl font-bold">Leopost</h1>
-      <p className="mt-4 text-gray-600">Setup in corso...</p>
+    <main className="min-h-screen flex flex-col items-center justify-center p-8 bg-gradient-to-b from-blue-50 to-white">
+      <div className="text-center max-w-2xl">
+        <h1 className="text-5xl font-bold text-gray-900 mb-4">
+          Leopost
+        </h1>
+        <p className="text-xl text-gray-600 mb-8">
+          Il tuo social media manager potenziato dall&apos;AI.
+          <br />
+          Minimo sforzo, massima resa.
+        </p>
+
+        <div className="flex gap-4 justify-center">
+          <Link href="/register">
+            <Button size="lg">
+              Inizia gratis
+            </Button>
+          </Link>
+          <Link href="/login">
+            <Button variant="outline" size="lg">
+              Accedi
+            </Button>
+          </Link>
+        </div>
+
+        <p className="mt-8 text-sm text-gray-500">
+          Nessuna carta richiesta. Piano gratuito disponibile.
+        </p>
+      </div>
     </main>
   )
 }