Type Alias CompactionFollowUp 

pub type CompactionFollowUp = Arc<dyn Fn(&str, &str, &DistillOutcome) + Send + Sync>;

Post-compaction follow-up hook (§8.6 trigger sequencing): invoked with (identity, session_key, outcome) after every compaction-cause distillation attempt, on the same detached task — so a wired Hygienist runs strictly AFTER the distiller’s harvest for that boundary.

Aliased Type

pub struct CompactionFollowUp { /* private fields */ }