Extremes do not always maximise — v0.2.0 candidate

Unrefereed theorem candidate with exact producer-side replay. The package gives a cardinality-minimal four-state monotone reversible counterexample to the general monotone-reversible clause of AIM Markov-chain mixing problem 1.6(1). It does not settle the separate zero-field Ising question, establish priority, or provide independent, formal, specialist, or peer-reviewed validation. DOI: 10.5281/zenodo.22163995.