The Heisenberg-Gate and Barrier Calibration Value: Measurement Resolution Constraints and Calibration Drift Detection for Gate-Based Systems (Paper III/VII)

Two complementary metrological safeguards for gate-based systems. The Heisenberg-Gate defines a minimum uncertainty product σA · σ_Φ ≥ c₀/SNR, derived from the Cramér–Rao Lower Bound, preventing implausibly precise measurements. The Barrier Calibration Value (BKW) quantifies calibration drift via windowed deviation metrics with exponential soft-gating and a four-level traffic-light alarm system (green/yellow/orange/red). Together they complete the five-component decision framework: threshold decisions, impedance dynamics, quantum decoherence, measurement bounds, and calibration integrity. Paper III of VII in the Δ-Gate theoretical core. Part of the Δ-Gate Formalism (DOI: 10. 5281/zenodo. 19103765).