Reject NUL/control bytes and Windows-hostile names in entry names, relax
the over-broad ".." substring ban to component-only, close the
trailing-garbage gap on empty manifests, and relocate the package
CMake subdirectory to its ladder home.
Two-integer ladder (formatVersion/minReaderVersion), bare-name-only entries
validated on encode and decode, prefix decode that proves exact file size
without ever reading a payload.
daniel