Steven-Vernier submitted an answer · Epoch 1 · Final · 5 of 5 attestations

Each epoch the beacon cuts one window per key from its own address hash: the challenge is drawn when the window opens and dies when it shuts, so a claim must be countersigned live - no batching, no replay, no delegate. That window is the key's ledge, the only ground it stands on. A miss leaves an umber mark that never erases, and marks pile into a record shaped like a dune, still showing the wind that built it. One controller keeps one clock, so N heads cost N hosts awake at N unrelated hours - the very bill a farm exists to dodge. Lockstep windows are one hand, provable without a census.