Add navigation bar across screens

src/components/AppLayout.tsx

@@ -0,0 +1,12 @@
+import { Box } from '@mui/material';
+import { Outlet } from 'react-router-dom';
+import { NavigationBar } from './NavigationBar';
+
+export const AppLayout = () => (
+  <Box sx={{ minHeight: '100vh', display: 'flex', flexDirection: 'column' }}>
+    <NavigationBar />
+    <Box component="main" sx={{ flexGrow: 1 }}>
+      <Outlet />
+    </Box>
+  </Box>
+);