Notify a wrapped behavior once after a relative delay.
Initialization first preserves the wrapped initialization actions, then
emits one generation-tagged ScheduleAfter request. A matching elapsed
event is consumed exactly once and folds on_elapsed; stale and duplicate
generations are inert unless the wrapped event sum independently accepts
them. Reaction sends, creations, and termination are preserved.
Reactions are infallible because they receive mutable access to the wrapped
behavior; ordinary delegated transitions retain the wrapped error type.
The timer never rearms. Generation exhaustion disables scheduling without
affecting the wrapped fold. These timer and ordering rules are Bombay
policy; sleeping and clock interpretation belong to bombay-timers.
Consume this definition, perform its one initialization fold, and
return the active behavior together with the ordered initialization
effects. Read more