Scout SourceAdapter

Scout is an optional external reference catalogue under adapters/scout-catalog/. Its 18 source declarations describe 61,590 normalized references without turning those records into Corpus Units.

The payload is not committed or fetched at query time. An operator supplies a data root. sources.yaml records provenance, licence text, field mapping, declared count, and digest for each source.

No data root produces an explicit SCOUT_DATA_ROOT_ABSENT diagnostic and zero references. Count or digest drift is also reported. The adapter never presents a missing payload as an empty successful search.

Scout is a SourceAdapter because a reference result needs an external URL, thumbnail, provenance, and licence. Kernary's in-corpus Candidate Generator returns Unit identities and feeds projection budgeting; forcing 61,590 external records into that contract would erase the distinction.

See adapters/scout-catalog/README.md for acquisition, sandbox registration, and payload verification.