compute_aux_w_p0b's stagnation term was firing inappropriately at
fold reset because Pearl-A first-observation bootstrap forces both
EMAs equal:
short_ema = sentinel 0.5 → first observation X
long_ema = sentinel 0.5 → first observation X (same update)
improvement = max(0, short - long) = 0
stagnation = (1 - 0/max(deficit, 0.005)) = 1.0
aux_w *= (1 - 0.7) = 0.3 → spurious decay on a non-stagnation
Fix: add epochs_in_fold parameter; skip stagnation when < 1. Wait
one full epoch for the α=0.3 vs α=0.05 short/long EMA timescale
split to produce real improvement signal.
Atomic refactor (feedback_no_partial_refactor): all 5 callers
migrated — 1 production site (training_loop.rs:4257) plus 4
existing unit tests at trainers/dqn/trainer/tests.rs.
Test: aux_w_stagnation_warmup_gate_epoch_0 verifies:
- Epoch 0: stagnation = 0, aux_w = base × deficit_amp = 0.625
- Epoch 1: stagnation = 1.0, aux_w = floor 0.15
Combined with A.2 (clamp lift), Fold 2's aux_w should now hit
0.625 in epoch 0 (the controller's intended post-deficit-amp
value) instead of being collapsed to 0.164.
Audit doc: Fix 41 added; stale "A.1 deferred" note from a prior
killed agent was also removed (A.1 lands in the next commit, not
deferred per user direction).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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