feat(01-01): initialize Next.js 16 project with TypeScript and Tailwind

- Next.js 16.1.6 with App Router and src/ directory
- TypeScript configuration with path aliases (@/*)
- Tailwind CSS v4 with PostCSS setup
- ESLint with Next.js config
- Supabase packages: @supabase/supabase-js, @supabase/ssr
- Form packages: zod, react-hook-form
- Simple Leopost placeholder page

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

src/app/page.tsx

@@ -0,0 +1,8 @@
+export default function Home() {
+  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>
+  )
+}