Computation pipeline

1. Read & validate inputs (min/max bounds, numeric checks, required fields).
2. Initialize compartments from totals and program settings.
3. Iterate time for the selected horizon (e.g., 100 days): update each compartment using rates.
4. Compute derived indicators (R₀, peak/day, duration, equilibrium where applicable).
5. Render plots (Chart.js curves) and update summary panels.
6. Export CSV/PNG/HTML using client-side downloads.

Quality checks (recommended)

• Non-negativity: compartments never go below 0 (clamp if needed).
• Mass sanity: totals stay within expected bounds (small drift acceptable if births/deaths included).
• Reproducibility: exported CSV matches plotted arrays (“what you see is what you download”).