REFACTOR(repo): simplify project structure

- Move services/nextjs to nextjs/
- Move deploy/docker/Dockerfile.prod to Dockerfile
- Add GitHub Actions workflows (ci.yml, build.yml)
- Remove deploy/, services/, scripts/ folders

nextjs/app/home/layout.tsx

@@ -0,0 +1,12 @@
+import { Navbar } from "@/widgets/landing";
+
+const MarketingLayout = ({ children }: { children: React.ReactNode }) => {
+  return (
+    <div className="h-full bg-white dark:bg-[#1F1F1F] space-y-20">
+      <Navbar />
+      <main className="h-full">{children}</main>
+    </div>
+  );
+};
+
+export default MarketingLayout;