# START HERE — V413 lateral lunge explicit foot contacts

Current checkpoint: `NEXT11_V413_LATERAL_LUNGE_EXPLICIT_FOOT_CONTACTS_FULL_ROOT`.

Read `HANDOVER_V413_LATERAL_LUNGE_EXPLICIT_FOOT_CONTACTS.md` first.

Production mapping:

- exercise: `lateral-lunges`
- profile: `warmup_lateral_lunge_ik_v1`
- resolved asset: `assets/nexprod/resolved/lateral-lunges-v413-explicit-foot-contacts.resolved.json`
- playback: `assets/nexprod/nexprod01-resolved-playback-v413.mjs`
- player: `assets/nexprod/nexprod01-resolved-player-v413.html`
- source film: `assets/media/exercises/lateral-lunges/source/NEXT11_dynamic_warmup_ijj7TD0DA6Q_lateral-lunges.MOV`
- duration: 6.6 s, two identical left-leading repetitions

The authoritative contact order is:

1. `R_Foot` is planted while `L_Foot` steps outward and loads.
2. `L_Foot` is planted while Nex rises and `R_Foot` gathers inward.
3. The same sequence starts again farther left in motion space.

V413 contains baked animation and baked camera follow only. Do not add a runtime foot solver.

Deterministic rebuild and verification:

```bash
node tools/nexprod/build_v413_lateral_lunge_explicit_foot_contacts.mjs .
node tools/nexprod/wire_v413_lateral_lunge.mjs .
node tools/nexprod/render_v413_explicit_foot_contacts.mjs .
node tools/nexprod/check_v413_explicit_foot_contacts.mjs .
```

The final checker must report `pass: true`, both planted-foot drift values below `2e-9 m`, continuous three-loop travel, and `liveSolverCalls: 0`.