Sub-ticket of MARS-122 DB (deferred/cold): 24 unindexed FKs on forensic/audit/housekeeping columns (archivedBy/deletedBy/restoredBy/resolvedByUserId/surrogateUserId/actorUserId/createdUserId/assignedTeacherUserId); none in hot paths; track, index only if a real query path emerges · mars