H-FMD/HYBRID-X: A Hybrid Pulsed-Induction and Low-Frequency Electromagnetic Architecture for Deep Subsurface Metal Detection and On-Device Material Discrimination — Reproducible Simulation Code, Corrections, and Results (v3)

Reproducible code, Monte Carlo/closed-form numerical results, and figure outputs for the companion manuscript "H-FMD/HYBRID-X: A Hybrid Pulsed-Induction and Low-Frequency Electromagnetic Architecture for Deep Subsurface Metal Detection and On-Device Material Discrimination: A Design and Simulation Study" (S. Farzaneh). v3 adds an editorial corrections pass (see H-FMD_Corrections_v3_Log.pdf) that corrected two closed-form numeric errors (Table X: gradiometer null-depth tolerance figure, depth-exponent sensitivity range) and re-verified all other closed-form claims in code. The original seeded Monte Carlo script and results (seed 20260814, NumPy Generator PCG64) are unchanged from v2 and are carried forward in this version.