Nav3 migration follow-up: Handle navigate back to ForYou

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Describe the problem

Figure out how the backStack should handle explicit navigations back to ForYou.

The current implementation would clear all sub stacks. So basically the backStack would be cleared with only a backStack[ForYou] left.

However this feels odd from a user's standpoint. But we also want users to be able to always exit out from ForYou.

### Describe the solution

.

### Additional context

_No response_

### Code of Conduct

- [x] I agree to follow this project's Code of Conduct

Start by tracing the Nav3 back-stack handling for explicit navigation to ForYou and compare it with the current behavior that clears sub-stacks. The issue names no files or tests and does not define the expected navigation outcome, so completion criteria need to be established before implementation.

Written by the indexing model from the issue text.