- Support optional domain context in Toon serializer metadata (@meta section now includes "context" property if provided).
- Update internal and public APIs to accept and propagate domain context.
- Add overloads for Serialize, SerializeTypeMetadata, and SerializeMetadata to allow specifying domain context.
- Add AcBinarySerializerIIdReferenceTests and AcJsonSerializerIIdReferenceTests to verify IId-based reference deduplication and reference identity for both binary and JSON serializers.
- Tests cover both int and Guid IId scenarios, data integrity, and output size efficiency.
