Stack is designed for layered, override-style state management.

Stack Root owns and manages the stack, while each Stack Layer defines its own lifecycle through Push, Resume, Update, Pause, and Pop. At runtime, only the top layer is actively updated, while the layers underneath remain paused until they are resumed. This makes Stack especially suitable for scenarios where one temporary layer needs to override another, such as a menu overlay pausing the game, a hit reaction interrupting movement, or a temporary interaction layer taking control over a base gameplay layer. The documentation also makes it clear that Stack is not a general-purpose scheduler and is not intended to replace FSM or BT.