SETCODEFROM 的悬空字节码：Ethereum 代码清理与 PBT 设计抉择

Every client already keeps bytecode that no account points at. That never mattered, because code sits outside the state root. SETCODEFROM lets any transaction add to the pile, and the partitioned binary tree moves code inside the root. Sync the same client twice, once with full sync and once with snap sync, and both no…