Test a full app with `devenv up`

[amitaibu]

We already have integration testing added in #2314

What if we had a full directory called ihp-app-test and inside a GH action, we would:

1. symlink IHP under it (/IHP)
2. Then we would run the tests
3. And on top of the integration tests, we could examine process-compose.log to test stuff like, a Job worker triggered. Currently, checking that devenv up is working, needs to be done manually in other projects

[amitaibu]

4. I don't know how complex it would be, bit it would have been amazing to have for testing being able to run with headless browser that allows JS. That would allow testing autoRefresh. If we can't integrate into hspec, so something like Playwright