Cabin CO2 Scrubber Compliance Monitor — 2D Trend View

This is the 2D companion to the 3D scrubber scene: the same mole-balance ODE for cabin CO2, driven by crew size and a two-bed 4BMS-style molecular sieve scrubber whose adsorbing bed saturates and whose desorbing bed regenerates on a tunable cycle. Instead of a rendered 3D cabin, the CO2 trend is drawn as a live scrolling strip chart against shaded NASA SMAC compliance bands, with a "time in compliance" audit metric and two bed-load bars tracking which bed is adsorbing versus desorbing at any instant. Push crew size up, stretch the cycle time until a bed saturates mid-cycle, or dial in a contamination leak, and watch the trace climb from the green nominal band through amber caution into red exceedance exactly as a real environmental control and life support system (ECLSS) compliance monitor would.