Development record

A host review can stay unlisted in the launch ledger. ListHostRole (internal/core/implement/loop/drive.go:171) writes the placeholder only after DriveReview returns, at the end of the step that handed the role out (internal/surface/cli/build.go:1317). A DriveReview that returns the run's busy lock skips it, a step killed between the two never reaches it, and a later step reads the await with handed false, so nothing lists the role afterwards and the run's listing shows fewer agents than it had.