cnjfl run showed val_loss and mean-AUC peak at different epochs:
epoch 3: val_loss=0.5592 (best) mean_auc=0.7608
epoch 4: val_loss=0.5609 (worse) mean_auc=0.7670 (best — new h300 + h6000 peaks)
val_loss tracks probability calibration; AUC tracks ranking quality.
For downstream trading the ranking profile matters more — so we now
publish both bests in alpha_train_summary.json and log a "new best
mean_auc" line whenever a new mean-AUC peak lands.
Early stopping still gates on val_loss (the two policies stay
decoupled — mean-AUC is reported-only).
New summary fields:
best_mean_auc_epoch
best_mean_auc
best_mean_auc_per_horizon
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>