Closes the TrainingPersist loop for the regime defense per the
KELLY_F_SMOOTH precedent (pearl_kelly_cap_signal_driven_floors).
Three layers:
(1) Per-step: alpha_regime_vol_update_kernel tracks min(vol_obs > 1e-12)
in new slot 553 (REGIME_VOL_OBS_MIN_INDEX). Filtered against artifact-
zero observations from stationary snapshots where curr == prev.
(2) Per-cell: stacker_threshold_controller_update gains a fifth branch
that reads vol_ref (slot 550) at cell-end, computes
`target = floor_target_ratio × vol_ref`, slow-EMAs the floor anchor
(slot 552) toward the target with rate `floor_update_rate` (0.1 per
cell). Subfloor 1e-12 inside the kernel guards against the anchor
collapsing to zero.
(3) Per-invocation: alpha_baseline reads
`config/ml/alpha_baseline_state.json` at startup and seeds slot 552
from the `regime_vol_ref_floor` field. At end of main(), the learned
floor is written back via tmp+rename atomic write so concurrent
walk-forward invocations see a consistent file. Matches the
cross-fold-persistent shape of KELLY_F_SMOOTH.
Block extended to 15 slots (539..=553). Smoke + kernel unit test
pass -1/-1 for the new floor-controller indices (backward compat).
Walk-forward CV verdict (Q1 fxcache, 3 sequential folds):
iteration fold-A fold-B fold-C mean ± SD
pre-defense (no regime) +91.52 -21.44 +46.74 +38.94 ± 56.88
hardcoded 1e-9 floor -19.77 +65.04 +6.45 +17.24 ± 43.42
learned floor (0.5 × cell_min) +74.78 -12.72 +8.80 +23.62 ± 45.59
learned floor (0.1 × vol_ref) -19.53 -26.51 +15.46 -10.20 ± 22.49
Controller infrastructure is structurally correct (loop closes, floor
persists across invocations, kernel + disk + ISV all roundtrip). The
TUNING is data-dependent — single-quarter CV doesn't have enough
regime diversity to anchor the floor against. Multi-quarter fxcache
validation is the next step (built cluster-side on the 9-quarter
2024-Q1..2026-Q1 ES futures dataset, downloaded as a single artifact
for local CV).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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