A concavity obstruction and repaired support reductions in a Frankl entropy programme — v0.2.0 candidate

Status: unrefereed candidate. This release identifies a counterdirection to a joint-concavity inference in Liu’s arXiv:2306.08824v1 and presents repaired support reductions with scoped exact and interval checks. It does not prove a new Frankl bound. Producer-side replay passed; independent specialist review, independent reproduction, and formal verification have not been established. Verify the frozen PDF and source bundle against SHA256SUMS.