Stepped-Wedge Clinical Trial Analysis and Power Simulation // Provides reusable functions for aggregated cluster-period data, mixed-effects analysis, and simulation-based power and type I error evaluation in stepped-wedge cluster randomized trials. The design and mixed-effects analysis follow Hussey and Hughes (2007) doi:10.1016/j.cct.2006.05.007. Intraclass correlations for binary outcomes are converted to logistic-normal random- intercept standard deviations following Eldridge, Ukoumunne and Carlin (2009) doi:10.1111/j.1751-5823.2009.00092.x. Monte Carlo uncertainty in estimated power is summarized using the exact binomial interval of Clopper and Pearson (1934) doi:10.1093/biomet/26.4.404. The simulation engine supports sequence-specific baseline risks, cluster random effects, direct intraclass-correlation specification, Monte Carlo uncertainty intervals, and model-fitting diagnostics. Applied physician and specialty helpers are retained for backward compatibility and for an example health-services workflow.