Ranking-Optimized Population Posterior Expected Percentiles // Implements the empirical Bayes ranking method described in Henderson and Hartman (2025) doi:10.48550/arXiv.2511.16530. The data structure of interest is a collection of cluster-specific effect size estimates, associated standard errors for these estimates, and cluster-level covariates. Estimates of the rankings of the cluster-specific effect sizes after adjusting for cluster-level covariates are generated.