FCLET-X1 Direct-Source Validation: Four-Configuration q≈0.93 Concordance, Analytic Fixed-q Closure, and Positive Bayesian Support

FCLET-X1 Direct-Source Validation: Four-Configuration q≈0.93 Concordance, Analytic Fixed-q Closure, and Positive Bayesian Support This dataset establishes the complete FCLET-X1 direct-source validation record across the Planck 2018 full-likelihood baseline, DESI DR2 BAO, Pantheon+SH0ES, three Planck-likelihood robustness configurations, the analytic fixed-q construction, the terminal fixed-q posterior, and Run-144A-S2 official-nuisance PolyChord support. The publication is generated locally from 85 SHA-256-matched source files totaling 522,585,507 bytes across four distinct working roots. It preserves raw posterior chains, recorded likelihood and launch configurations, analytic inputs and formula source, terminal convergence logs, original S2 logZ files, machine-readable calculations, and the executable reproducer. The central empirical result is a stable q≈0.93 response. The baseline raw-chain recomputation returns q_FCLET = 0.930202441 ± 0.012726738 and FCLET H0 proxy = 73.7314 ± 0.9754 km s^-1 Mpc^-1. The baseline observed-chain comparison favors FCLET with Δχ²(FCLET−LCDM) = -26.5542 and a one-additional-parameter ΔAIC diagnostic of -24.5542. Across the baseline, Planck no-lensing, TT-only, and Plik-lite configurations, the q posterior means occupy the narrow span [0.929110546, 0.930202441]. The analytic construction returns q_theory = 0.929980222562455, located inside that span and inside the central 68% and 95% intervals of all four empirical posteriors. Each of the four observed-chain fit comparisons favors FCLET. With q fixed at the analytic value, the terminal posterior contains 15,400 rows and returns H0 = 68.5485 ± 0.2743 km s^-1 Mpc^-1 and H0 proxy = 73.7097 ± 0.2950 km s^-1 Mpc^-1. The recorded terminal convergence values are R−1 = 0.008526 for means and R−1 = 0.076427 for bounds. Run-144A-S2 adds a positive Bayesian support result: the official-nuisance PolyChord comparison gives ΔlnZ(FCLET−LCDM) = +1.353501 ± 1.658864 and point Bayes factor FCLET/LCDM = 3.870955. The complete S2 source archive, both original logZ files, PolyChord statistics, configurations, content hashes, archive checksum, and CRC verification make the result directly inspectable.