Compare Model Population to Population Reference Estimates

This function compares the population from the model output (`model_run`) to UN World Population Prospects (reference population) data. It returns:

Usage

demographic_check(reference_population, model_run, age_breaks)

reference_population: A matrix or data frame of reference population data, where each column is a year and each row is an age group. Values should be in thousands. Typically from data_load_process_wrapper.
model_run: A data frame of stratified model output, including `time`, `age`, `state`, `value`, `vaccination`, and `risk`. Typically from summary_plots.
age_breaks: A numeric vector of age group breakpoints (e.g., `c(0, 5, 10, ..., 80, Inf)`).

A named list with:

population_plot: A `ggplot` object comparing total population by year.
age_breakdown_plot: A `ggplot` object comparing age distribution in the final year.

1. A line plot comparing total population over time. 2. A bar plot comparing the age distribution in the final year.