A Practitioner's Gate-Calibration Toolkit: From Cramér–Rao Bounds to Logit-Gate Decisions in Noisy Quantum Systems (Paper VII/VII)

Self-contained, deployable five-stage gate-calibration pipeline for noisy quantum systems Stage 1: Cramér–Rao precision floor with Heisenberg-Gate constraint. Stage 2: AR(1) signal conditioning with Kalman filtering and Huber-robust outlier rejection. Stage 3: four coherence metrics (HBT, relative entropy, percent-coherence, absolute normalized). Stage 4: universal Logit-Gate with closed-form two-parameter calibration (x₅₀, slope s). Stage 5: BKW drift surveillance with traffic-light alerting. Includes worked transmon readout example, default parameter table, gate-composition protocol, and time-crystal scheduling. Platform-agnostic. Paper VII of VII — engineering capstone of the Δ-Gate series. Part of the Δ-Gate Formalism (DOI: 10.5281/zenodo.19103765).