Changes touching this path

• every open of a compressed object stops building a fresh zstd context and asking for a 64 MiB buffer, because the decompressor is now thread-local and the buffer is the frame's own declared size clamped by the same zip-bomb ceiling, and the harness gains the first fixture whose objects are actually compressed - without which nothing could have seen the 72.6% it removed (#1424) 7c16d4d4 · 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.