`snapshotJsonValue` left @deepseek-ai/dsh-session in 0.1.2-alpha.2 (moved to dsh-util-values). Inline the same validate-and-detach semantics in the fold driver helper so the specs compile and run against every supported dsh face.
`snapshotJsonValue` left @deepseek-ai/dsh-session in 0.1.2-alpha.2 (moved to dsh-util-values). Inline the same validate-and-detach semantics in the fold driver helper so the specs compile and run against every supported dsh face.