feat: scaffold monorepo with Turborepo + NestJS + Next.js

- Turborepo monorepo with pnpm workspaces
- apps/api: NestJS 11.x with CQRS module
- apps/web: Next.js 14 App Router + TailwindCSS
- src/modules/shared: base entities, Result pattern, value objects
- TypeScript 5.7+ strict mode, shared tsconfig base
- Build pipeline: dev, build, lint, test, typecheck

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/web/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">GoodGo Platform</h1>
+      <p className="mt-4 text-lg text-gray-600">Vietnam Real Estate Platform</p>
+    </main>
+  );
+}