Solver configuration roles

The comparison unit is a versioned core, runtime path, physical model and numerical configuration. MuJoCo PGS/nonlinear CG/Newton are alternative constraint methods; SuperDex Newton and GMRES are outer and inner methods. Cloth implementations, contact models, approximations, integrators and update budgets are not peer algorithms.

The complete bilingual role guide explains each engine, source evidence, system-profile selection versus algorithm attribution, and unresolved identities. The display vocabulary never changes recorded scores, counts or qualification.

Full configuration matrix · Diagnosis · Current work and pause state

Fine-feature SDF validation is tracked in #178, and cloth material/contact baselines in #179. Their creation is not experimental acceptance. Historical task success remains distinct from numerical consistency and real-material fidelity.