feat(aux-supervision): wire BCE + conditional-Huber actual calls (CB5)
CB3+CB4 shipped the kernels with a holding-pattern (grad-zero) call site.
CB5 wires the real calls + per-loss ISV signals.
perception.rs:
- step_batched body: pos_weight computed host-side from
self.last_pos_fraction (n_neg/n_pos clamped to [1.0, 50.0] per E3),
uploaded mapped-pinned to stg_aux_pos_weight_{long,short}
- 4 kernel calls per step (slab mode, K*B*N_AUX_HORIZONS):
* aux_bce_loss_gpu × 2 (prof_long, prof_short) — class-weighted
* aux_huber_masked_loss_gpu × 2 (size_long, size_short) — NaN-mask
from CB1's y_size=NaN at y_prof=0 gives conditional-Huber for free
- Per-loss EMAs replace single aux_huber_ema:
* aux_prof_bce_ema_per_h (BCE EMA per horizon)
* aux_size_huber_ema_per_h (Huber EMA per horizon)
* aux_dir_acc_ema_per_h (unchanged)
- Stop-grad lift condition: aux_prof_bce_ema < 0.4 AND aux_dir_acc > 0.85
for ALL horizons (uses BCE not Huber per E3 — size Huber is
observability-only since the regression scale varies more than the
binary classification quality)
- aux_lift_huber_threshold renamed to aux_lift_prof_bce_threshold
alpha_train.rs:
- AlphaTrainSummary: final_aux_huber_ema_per_h split into
final_aux_prof_bce_ema_per_h + final_aux_size_huber_ema_per_h
- Per-epoch tracing: aux_prof_bce_h{100,300,1000} + aux_size_huber_h{...}
+ aux_dir_acc_h{...} + stop_grad_aux_to_encoder
perception_overfit.rs: synthetic test asserts BCE finite + below ln(2)
chance baseline, size Huber finite, dir_acc >= 0.5.
Synthetic test on RTX 3050:
aux_prof_bce_ema = [0.0142, 0.0142, 0.0142] (30× below threshold)
aux_size_huber_ema = [0.1213, 0.1213, 0.1213] (small)
aux_dir_acc_ema = [1.0, 1.0, 1.0] (perfect)
stop_grad lifted = false (lift fired)
Known limitation (follow-up CB6): both kernels return single joint scalar
over the [K × B × N_AUX_HORIZONS] slab — all per-horizon EMA entries
carry the broadcast joint mean. Per-h gating would require kernel split.
cargo check --workspace --all-targets clean.
cargo test -p ml-alpha --lib: 43 passed.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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