Nested backing class emits $-qualified names at the no-Class-in-hand emit sites (backingClassOf, recordColumnReadArgs, FetcherEmitter, ChildField)

R370 fixed the ClassName.bestGuess(binaryName) nested-class defect (a nested backing class emits the non-compiling Outer$Nested instead of the JLS-legal Outer.Nested) at the four sites that had a structurally-correct name already in hand: the two AccessorRef producers, the @service return-type validator (checkServiceReturnMatchesPayload), and the @service fetcher return type (computeServiceRecordReturnType). The same bestGuess-over-fqClassName() hazard recurs at a family of emit sites that hold no reflected Class<?> and no captured structural TypeName, so they cannot take R370’s one-for-one call swap:

The structural fix for these is to carry the backing class as a ClassName on the model (the way AccessorRef already carries parentBackingClass) rather than re-parsing a binary string at emit time; a model-shape change with its own blast radius. Latent for the same reason R370’s core bug was: no nested carrier exercises these paths under compilation today. Scope, enumerate the exact sites, and decide the model-lift shape when this moves to Spec; R370’s Scope-note and Sibling-latent-bug sections are the starting map.