feat(sp22-vnext): Phase B0 — AuxTradeOutcome ops struct scaffolding
First Rust-side commit of Phase B for the SP22 H6 vNext trade-outcome
aux head. Pure orchestrator scaffolding mirroring AuxHeadsForwardOps /
AuxHeadsBackwardOps. Zero production callers — additive per the
gpu_grn / aux_trunk commit-by-commit ordering convention (scaffold
→ trainer fields → collector wireup).
Adds:
- gpu_dqn_trainer.rs: 4 cubin embeds (TRADE_OUTCOME_LABEL_CUBIN,
AUX_TRADE_OUTCOME_FORWARD_CUBIN, AUX_TRADE_OUTCOME_LOSS_REDUCE_CUBIN,
AUX_TRADE_OUTCOME_BACKWARD_CUBIN). All #[allow(dead_code)] until B1+.
- gpu_aux_heads.rs: AUX_OUTCOME_K = 3 constant (parallel to AUX_NEXT_BAR_K).
- gpu_aux_heads.rs: AuxTradeOutcomeForwardOps struct holding 3 kernel
handles (forward + loss_reduce + label producer). Launch methods:
forward(), loss_reduce(), compute_label(). Per-env label kernel uses
grid ceil(n_envs/256) — pure per-env map, no reduction.
- gpu_aux_heads.rs: AuxTradeOutcomeBackwardOps struct holding 1 kernel
handle (backward). Launch method: backward(). Reuses existing
K-generic aux_param_grad_reduce from AuxHeadsBackwardOps — no
separate reducer needed.
Contract shapes mirror AuxHeadsForwardOps/AuxHeadsBackwardOps so
subsequent wireup commits plug in with minimal contract drift. Phase B
proper (input concat 256→262 with plan_params) becomes a small change
touching only the buffer fill + W1 shape once B1-B4 land the wireup.
Phase B1 next: trainer struct fields for W1/b1/W2/b2 + Adam state +
Xavier init + reset registry entries.
Audit: docs/dqn-wire-up-audit.md Phase B0 section.
Cargo check clean (21 warnings, none new).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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