TRAINER BARN HOT

Pre-computed before the per-horse loop: if a horse's last-race performance exceeds the average of its two prior figures by more than 2 points, it counts toward the trainer's improving-horse tally. When two or more horses from the same trainer meet that threshold on the same card, all of that trainer's entrants receive TRAINER_BARN_HOT. A hot barn signals that the trainer's current conditioning program is working across multiple horses simultaneously — it is a barn-level fitness indicator that transcends the individual horse's form and is especially useful when a horse's own figures do not stand out.