feat: implement Sleepy sleep diary

app/layout.tsx

@@ -0,0 +1,17 @@
+import type { Metadata, Viewport } from 'next';
+import { ServiceWorker } from '@/components/ServiceWorker';
+import './globals.css';
+
+export const metadata: Metadata = {
+  title: 'Sleepy - дневник сна',
+  description: 'Простой дневник сна для наблюдения за динамикой.',
+  manifest: '/manifest.webmanifest',
+  icons: { icon: '/favicon.svg', apple: '/favicon.svg' },
+  appleWebApp: { capable: true, title: 'Sleepy', statusBarStyle: 'default' },
+};
+
+export const viewport: Viewport = { themeColor: '#f5f4ed' };
+
+export default function RootLayout({ children }: Readonly<{ children: React.ReactNode }>) {
+  return <html lang="ru"><body><ServiceWorker />{children}</body></html>;
+}