Module serialize 

Round-trip every ModelDiff variant through a pf_core::cas::BlobStore.

Wire format model.diff.v1: a single JSON blob containing a tagged ModelDiff. We rely on serde_tagged semantics from the enum’s #[serde(tag = "kind")] for the discriminator. Validation + canonicalization happen on store; layout-version check happens on load.

Functions

load_diff

Load a ModelDiff previously written by store_diff.

store_diff

Validate, canonicalize, and persist a ModelDiff into blobs. Returns the digest of the resulting blob.