The runtime target is Schema.String (or the supplied domain), but decoded
values are Domain by construction — both the labels table and fallback
produce Domain. This is the one place the engine states a Schema.Codec<…>
explicitly rather than inferring, because no runtime schema captures the
"labels ∪ fallback results" set.
The schema a lookup factory produces.
The runtime target is
Schema.String(or the supplieddomain), but decoded values areDomainby construction — both thelabelstable andfallbackproduceDomain. This is the one place the engine states aSchema.Codec<…>explicitly rather than inferring, because no runtime schema captures the "labels ∪ fallback results" set.