reorg ui into app

lib/app/screens/now_playing_screen.dart

@@ -0,0 +1,26 @@
+import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
+
+class NowPlayingScreen extends StatelessWidget {
+  const NowPlayingScreen({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: Center(
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: [
+            Text('Now Playing!'),
+            TextButton(
+              onPressed: () {
+                context.go('/album');
+              },
+              child: Text('Album...'),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}