Changes touching this path

• the relay contract is asserted once and both backends run it, the mailbox choreography moves behind a blanket impl a backend cannot override, and the fs and bucket acks stop disagreeing about which of them was right (#1164) eb659a91 · dbf3dbe6…

Renames are not followed. loot's tree maps a path to an address, so a rename is a delete and an add. This list is the history of the name, not of the bytes.