rememberLayerAnimationState
Manages animation state for content layer screen transitions
Strategy:
Forward navigation (A → B): Keep both A and B composed; A preserved for back navigation
Back navigation (B → A): Keep both during animation, dispose B after completion
Previous entry is tracked locally in Compose and cleared after animation duration. This avoids storing animation state in NavigationState.
Return
Animation state containing current, previous, and all entries to keep composed
Parameters
currentEntry
The currently active screen entry