Saves a list of fitted PI models as individual RDS files.
save_PI_models(models, output_dir, prefix = "model_")Character vector of saved file paths (invisibly).
Creates the output directory if it doesn't exist. Each model is saved
as {prefix}{i}.rds (e.g., model_1.rds, model_2.rds, ...).
if (FALSE) { # \dontrun{
models <- list(model1, model2, model3)
save_PI_models(models, "output/piModels/")
} # }