Version of the cache directory schema. Bumped whenever the on-disk layout (file names, meta-file shape, or ModelDescriptor JSON structure) changes in a way that would mis-deserialize older entries.
ModelDescriptor
Returns the conventional cache root, ~/.ksl/bundle-cache.
~/.ksl/bundle-cache
Streams the file's bytes through SHA-256 and returns the digest as a lower-case hex string. Used as the per-JAR cache directory name.