SerializeWorld returns owned Bytes; Bytes_Data borrows their byte array.

Release the owner with FreeBytes after copying or consuming it. DeserializeWorld creates a new owned world. DeserializeRigidState is a separate importer for legacy Rust testbed rigid-state snapshots. Only load trusted snapshots produced by the identical Rapier build. Snapshots are not a durable interchange format.

Old handles still point to the original world. Discard them and enumerate handles from the restored world. Configure any thread pool and external callback/user state again; application-owned state is not reconstructed automatically.