Phase A3 of the SP22 H6 vNext trade-outcome aux head (per
docs/plans/2026-05-14-sp22-h6-vNext-trade-outcome-aux.md). Two atomic pieces:
1. NEW kernel `aux_trade_outcome_forward_kernel.cu` — K=3 softmax aux head
forward (Linear → ELU → Linear → stable softmax). Mirrors
`aux_next_bar_forward` (K=2) but emits {Profit, Stop, Timeout} probs.
Saved tensors {hidden_out, logits_out, softmax_out} ready for A4 (loss
reduce) and A5 (backward). Dead code at this commit — no Rust launcher
yet. Registered in build.rs::kernels_with_common, cubin verified.
2. Save-for-backward buffers `pnl_vs_target_at_close_per_env` +
`pnl_vs_stop_at_close_per_env` ([alloc_episodes] f32 device-resident).
Producer: `experience_env_step::segment_complete` writes the trade's
realized P&L ratios vs profit_target / stop_loss at close (inline-
computed from `pre_trade_position × (raw_close − entry_price) /
(ps[PS_PLAN_PROFIT_TARGET] × prev_equity)`, symmetric-clamped to
[-2, +2] per pearl_symmetric_clamp_audit — same formula as the
sibling experience_state_gather's plan_isv[PLAN_ISV_PNL_VS_TARGET/_STOP]
slots). Consumer (eventual A4/A5 wireup): trade_outcome_label_kernel
classifies each close into {Profit, Stop, Timeout} via the ≥1.0
threshold-hit predicate.
Wireup discipline per feedback_registry_entries_need_dispatch_arms:
- New struct fields on GpuExperienceCollector
- stream.alloc_zeros at construct site
- Kernel-launch .arg() threading at experience_env_step launch
- StateResetRegistry entries (FoldReset sentinel 0.0)
- training_loop::reset_named_state dispatch arms
- All 10 registry pin tests pass including
every_fold_and_soft_reset_entry_has_dispatch_arm
Audit doc updated: docs/dqn-wire-up-audit.md Phase A3 section.
Next phases (per spec): A4 = aux_trade_outcome_loss_reduce (sparse CE,
mask=-1), A5 = aux_trade_outcome_backward, Phase B = 262-dim input
(h_s2_aux || plan_params), Phase C = 3-slot state assembly, Phase D =
12-weight W atom-shift, Phase E = dW + Adam, Phase F = validation smoke.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
07728f9efc