Cubical Agda Merge — Discharging the Boundary Postulates B1–B4

Abstract

Discharges boundary postulates B1–B4 from Vol IV in Cubical Agda with --safe --cubical flags. Machine-checks contract-k1 (ζ(2)/2 = π²/12) and contract-k2 (ζ(4)/2 = π⁴/180) as isContr proofs. 35 valid theorems at 2.3× target, 1 incomplete.