Oracle-Free Verification of a Constructive Geometric Constant π_g

This technical note provides an oracle-free numerical verification of the constructive geometric constant πg\pi_g, defined from a cubic refinement recurrence and its associated polygonal limit. Version 2.2.0 implements nine declared consistency checks, including the constructive recurrence, scale relations, Richardson acceleration, independent high-precision comparisons, and an a priori Richardson tableau enclosure. All nine checks pass at 120-decimal-digit working precision. The deposit includes the synchronized verification report, reproducibility materials, package manifest, SHA-256 checksums, and source archive corresponding to GitHub release v2.2.0. The computational results provide reproducible numerical evidence and consistency checks for the stated identities. They should not be interpreted as replacing the analytic proofs required for exact mathematical identification.