lateinit var vs. val by lazy in Android

This tests your grasp of Kotlin's non-nullable property initialization strategies and their trade-offs in mutability, thread safety, and performance in Android. A strong answer defines `lateinit` as a mutable promise for external initialization (like in `onCreate`) and `lazy` as an immutable property whose expensive creation is deferred until first access. Give clear examples: `lateinit` for a RecyclerView adapter and `lazy` for a heavy ViewModel. A common red flag is suggesting `lazy` for a property that needs to be reassigned.