Data and code for: A hyperbolic Kepler equation solver with four Newton iterations and a computer-assisted uniform error bound

Source code and data for the article "A hyperbolic Kepler equation solver with four Newton iterations and a computer-assisted uniform error bound". The Python scripts implement the solver, check the error bound on a verification grid and in interval arithmetic, benchmark accuracy against reference solvers, and generate the error-map and Newton iteration-count figures. Data: bound_check_summary.json (verification-grid results), benchmark_accuracy.json (benchmark accuracy and function evaluation counts, with platform metadata), grid_error_maps.npz (error-map and iteration-count grids), corner_transect_naive_stable.csv (errors along M = ε³), independent_root_crosscheck.json (independent root cross-check), interval_certification.json (interval-arithmetic check of the constants). Reference roots use the mpmath library at 50 significant digits; random grids use seed 20260720. Version 1.1.1 accompanies the revised manuscript. It removes the timing, throughput, and Fukushima comparison material of version 1.0.0, adds the Newton iteration-count map, extends the interval-arithmetic check to every rounded constant printed in the paper, and uses only the published starter of Avendaño et al.