Expo router project not importable to snack?

### Summary

When trying to import [repo](https://github.com/Twiggeh/react-native-paper-bug-report) it errors with App.js missing in the project, but for expo router projects App.js is no longer the entry.

I tried looking for expo router specific things in snack, but didn't find anything

### What platform(s) does this occur on?

Android, iOS, Web

### SDK Version

49.0.8

### Reproducible demo or steps to reproduce from a blank project

Importing this repo doesnt work
https://github.com/Twiggeh/react-native-paper-bug-report

Start by reproducing the import of Twiggeh's react-native-paper-bug-report repository in Snack and inspect how the project entry point is detected when App.js is absent. Compare that behavior with Expo Router's entry-point expectations; done means an Expo Router project imports successfully and runs on Android, iOS, and Web.

Written by the indexing model from the issue text.