ExtractionRunFingerprints

The digests that say what a run ran against.

All three are opaque to DICE: it compares them and stores them and reads nothing out of them. They are what makes "did the output change because the prompt changed?" answerable without storing the prompt. A host that changes a template and forgets to change its fingerprint gets runs it cannot tell apart, which is the host's contract to keep.

Storing a digest and leaving the material behind is deliberate: a prompt template holds instructions and often examples, and examples are where real content ends up.

Who writes metamodelFingerprint. The extraction coordinator, which arrives in a later slice. It reads the declared schema stamp from the host's DeclaredSchemaSource, hashes the content, and writes the hash here, once per run. Nothing in this slice produces one, so a run built today carries whatever its caller passed.

The fingerprint says what the whole run ran under. Asking which schema a single proposition was extracted under is answered by following that proposition back to its run through run lineage, which is why no per-proposition schema stamp exists.

EXPERIMENTAL. The shape may still change while extraction runs (DICE #67) land.