Inter-stage container

Subclasses MultiAssayExperiment. The four added slots carry schema versioning, ordered provenance, sampling-design declaration, and (for synthetic data) the answer key. Everything else lives in the MAE slots or in S4Vectors::metadata() as private scratch.

Slots

schema_version

semver string, e.g. "0.2.0"

provenance

ordered list of ProvenanceStep objects

ground_truth

GroundTruth subclass or NULL

sampling_design

SamplingDesign declaration attached by the user via declare_sampling_design. The kind = "unspecified" default is set by the migration and causes Stage 2 to reject the object until the user makes an explicit declaration.