Compares each computed metric against optional per-model thresholds
from model_config.simple_metrics_thresholds. Convention:
- {metric}_max: breach when value > threshold (rmse, mse, mae)
- {metric}_min: breach when value < threshold (r2)
Fires WARNING notification on breach. Missing thresholds = no alerting.
Schema designed to be extensible for Card 2 (Drift) thresholds.
SIENTIAPDE-1986
5997210118