# HyperTwist Phase J-B regression snapshots and cross-run benchmark deltas implementation packet

## Status

`Phase J-B` is now landed locally as the second bounded HyperTwist-native
validation and benchmarking slice.

## Landed surfaces

- regression-snapshot contract
- cross-run benchmark-delta boundary

## Code

- extended bundle and regression/delta contract structs in
  `UnrealHyperTwist/Source/UnrealHyperTwist/Public/HyperTwistTraining/HyperTwistTrainingValidationBenchmarkLibrary.h`
- bundled contract data and query functions in
  `UnrealHyperTwist/Source/UnrealHyperTwist/Private/HyperTwistTraining/HyperTwistTrainingValidationBenchmarkLibrary.cpp`
- runtime accessors in
  `UnrealHyperTwist/Source/UnrealHyperTwist/Public/HyperTwistTraining/HyperTwistTrainingRuntimeLibrary.h`
  and
  `UnrealHyperTwist/Source/UnrealHyperTwist/Private/HyperTwistTraining/HyperTwistTrainingRuntimeLibrary.cpp`
- focused automation in
  `UnrealHyperTwist/Source/UnrealHyperTwist/Tests/HyperTwistValidationPhaseJBRegressionDeltaContractTest.cpp`

## Boundaries preserved

- keep snapshots and deltas first-party and runtime-evidence local
- do not widen into experiment trackers or artifact warehouses
- do not widen into public leaderboards or telemetry platforms
- do not widen into automated release promotion authority

## Canon result

- `Phase J-A` and `Phase J-B` are now landed as the first bounded validation
  and benchmarking scaffold in current code
- the then-next deliberate seam, `Phase J-C` validation evidence exports and
  benchmark fixture packets, is now also landed
