Modular Bayesian Hierarchical Shrinkage Models // Implements a two-stage Bayesian hierarchical modeling framework for applying shrinkage to subgroup-specific effects. The package separates model fitting (Stage 1) from hierarchical shrinkage (Stage 2), enabling modular sensitivity analyses without refitting expensive Markov chain Monte Carlo (MCMC) chains. Supports flexible prior specifications through the 'distributional' package, mixture approximations via 'mclust', and efficient 'Stan'-based inference.