Verify the practical benefit of propagator actions

Verify whether incorporating propagator actions into the unified atomic action space for SCIP presolve yields measurable performance gains, beyond their formal availability in the execution interface and sequence-generation framework.

Background

ORDO defines a unified action space spanning standalone presolve routines, propagator callbacks, and constraint-handler callbacks. However, the experimental corpus contains no propagator actions, so the empirical results primarily concern the other two action families. The authors therefore leave unresolved whether the propagator portion of the action space can contribute useful performance improvements when it is actually exercised.