# Next-Session Follow-Up Prompt for SP22 H6

Paste this into the next session to pick up cleanly:

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Hi — picking up SP22 H6 implementation from yesterday's session.

**Context**: We closed SP21 T2.2 (cascade wiring complete + eval pipeline fixed via 4-layer peel: 8.3+9, 8.5, 8.7, 8.4-fix). v10 hypothesis test confirmed WR is structurally pinned at 50.1-50.2% across all training durations and cascade configurations.

H1 (label horizon) was falsified: aux head learns 78% directional acc at H=200 within-fold, but the policy is walled off via trunk separation (`pearl_separate_aux_trunk_when_shared_starves`).

**Current hypothesis**: H6 — wire aux head's directional probability into policy STATE so the policy can use the proven directional signal. Detailed implementation runbook at:

  `docs/plans/2026-05-12-sp22-h6-aux-policy-state-bridge.md`

That doc has all 10 implementation steps with file paths, kernel signatures, and the verification protocol.

**State of the world**:
- Branch: `sp20-aux-h-fixed`, HEAD = `f50a974fb` (docs commit; H1 reverted at `e8814079d`)
- All training-side fixes (Phase 8.2/8.4/8.4-fix/8.6) are live
- Eval pipeline works end-to-end (compute-sanitizer 0 errors locally)
- No active workflows or monitors
- Local GPU (RTX 3050 Ti) + compute-sanitizer available for fast iteration

**Today's goal**: Execute Steps 1-10 of the H6 runbook. Phase 1 (training-side + eval A3 fallback) only. If smoke shows WR > 50.5%, follow up with A2 (eval-side aux integration). If WR pinned, hypothesis falsified — pivot to H3 (reward density) or audit V/A.

**Verification gates** before smoke dispatch:
1. `cargo check -p ml --features cuda` clean
2. `gpu_backtest_validation` tests pass
3. `compute-sanitizer --tool=memcheck` 0 errors

**Then**: dispatch standard baseline smoke, watch cycle 1 WR. ~2 hours wall-clock to verdict.

Start by reading the runbook, then begin Step 1 (state layout constants).
