4×8 lamp failure and exhaust fan failure are undetectable: both report commanded state; no derived check (tent temp / CO₂ draw-down in the light window, temp ri

Dev-bed sweep cases lamp_failure (4×8) and exhaust_failure: nothing raised in 3 virtual h. The 4×8 lamp is open-loop by design (the hub cannot see it), and fans report duty not airflow, so a direct check is impossible — but the effects are observable: no canopy CO₂ draw-down and no lamp heat during the light window; tent temp above room while exhaust is at high duty. A ‘suspect’ alert from those derived signals would catch both.