DriftQuarantineKeys

Metadata keys drift quarantine writes onto a proposition, alongside the shared com.embabel.dice.common.DiceMetadataKeys.QUARANTINE_REASON.

They live here because drift quarantine is the only thing that writes or reads them, and the core proposition model has no business knowing about schema versioning. The naming follows the same dice.<area>.<name> convention, so nothing collides with a consumer's own keys.