refactor(App, navigation): migrate to Expo Router and clean up navigation structure

- Updated App entry point to utilize Expo Router, simplifying the navigation setup.
- Removed legacy navigation components and services to streamline the codebase.
- Adjusted package.json to reflect the new entry point and updated dependencies for compatibility.
- Enhanced overall application structure by consolidating navigation logic and improving maintainability.

app/(app)/(tabs)/messages/_layout.tsx

@@ -0,0 +1,5 @@
+import { Stack } from 'expo-router';
+
+export default function MessagesStackLayout() {
+  return <Stack screenOptions={{ headerShown: false }} />;
+}