Constraint-Driven Cosmology (CDC): Thermodynamic and Consistency Gates on Late-Time Expansion

CDC (Constraint-Driven Cosmology) is a gate-based inference framework that constrains admissible late-time expansion histories using auditable physics requirements rather than flexible equation-of-state parameterizations. Gates include: units/symbol hygiene, conservation closure, baseline limit recovery, horizon-thermodynamic null tests (apparent-horizon entropy constraints), and distance–growth consistency in GR. CDC turns these constraints into operational diagnostics (PASS/FAIL + failure localization) and provides a reproducibility checklist and pipeline pseudocode.This release includes synthetic-data validation and a minimal real-data demonstration section (cosmic chronometer H(z)H(z)H(z) reconstruction with a NEC/horizon diagnostic), designed to illustrate how the gate logic stabilizes reconstructions and localizes tension between observational sectors.