Impact-aware active-learning ranker: uncertainty × volume × drift

The active-learning queue used to rank candidates by |p − 0.5| alone (uncertainty sampling, Lewis 1994). It treated a Mali day with 1 measurement the same as an Iran day with 762. The new default ranking is a 3-factor product — uncertainty × log-volume × DBSCAN drift — heuristic Estimated Error Reduction in the spirit of Settles 2009. Toggle back to the old ranking via ?rank_by=uncertainty. Live at /v1/sentinel/active-learning-queue.