UCT Prediction 2 — Stage 3: Result-of-Execution Report (IBM Fez Z_2^3 Branch)

Honest result-of-execution report documenting the outcome of testing the UCT compression-interface (Z_2)^3 prediction on IBM Fez (qubits 15, 25, 56) under the pre-registered Stage 1 / Stage 1b / Stage 2 lock chain. Locked operational estimator returned f̂ = 0.87500 exactly, matching the (Z_2)^3 prediction f = 7/8 to all decimal places, with bootstrap σ(f̂) = 0 (200 replicates). The singular-value spectrum of the symmetrized POVM matrix shows a clean 40× gap (σ_1 ≈ 1.00, σ_2 ≈ 0.025), confirming