# V6.6 — Dynamic Warmup exercise 9 Lateral Lunges

Base: V6.5 locked fullroot.

## Outcome
- Exercise 9 uses the existing V425 contact-corrected resolved asset.
- Resolved playback uses the shared V412 runtime.
- Presentation heading is -90 degrees relative to runway travel, so travel is lateral relative to Nex.
- Camera rotates the frozen front/three-quarter basis with the presentation heading.
- Exercise 8 Reverse Lunges regression remains backward (`travelDirectionSign=-1`).

## QA
- `preview.html?workout=dynamic-warmup#pass`: PASS for exercise 9 boot/canvas and visual front/three-quarter composition.
- Exercise 9 telemetry: `presentationFacingYawDeg=-90`, `cameraHemisphereSign=1`, `cameraTracksModel=true`.
- Exercise 8 regression: PASS; observed `travelZ<0` when travel is active.
- Long Chromium sessions remain sandbox-unstable; loop camera continuity is also proved structurally because camera and target share the exact same `travelZ` translation and only a constant rotated relative camera basis is added.

## Frozen boundary
- Resolved motion/model changes: 0.
- No new IK or solver.
- Exercises 1-8 retain heading 0 by default and therefore the V6.5 camera equation exactly.