To make the serializer extensible and provide space for writer-specific information, we need to introduce a meta-record type. This will allow additional metadata to be embedded alongside the canonical state while preserving the integrity of the format.

Goals

• Define a meta-record structure that can be included in the pack format.
• Update both the reference implementation and the production serializer to support this record type.
• Ensure compatibility with CIP specifications, by updating either implementation or spec

Specification

Gist of the spec:

A meta-record will store a list of entries.

Each entry is a pair of:

• A description string in URL format (to identify the metadata type).
• A CBOR-encoded value.

Deliverables

• A formal definition of the metadata record.
• Updates to the reference and real implementations to support this record type.
• Tests demonstrating correct handling of meta-records (serialization, deserialization, and validation).
• Agreement on any deviations from the CIP description, with updates recorded in implementation-choices.md if necessary.