VIOLET V3.2: EsoF size-modulation fold (BLUE SC haircut, exact)

modulation.py: VioletSizeModulation wraps BLUE's canonical esof_size_mult_from_score
+ esof_score_from_payload (exact ESOF_* constants), applies the SC haircut
step-for-step as _apply_sc_entry_size_multiplier (nautilus_event_trader.py:3307):
mult clamped [0,1] HAIRCUT-ONLY (:3316), near-1 no-op (:3318), round(lev*mult,6)/
round(notional*mult,12). 8 tests pass. Empirical mult-recovery on recorded BLUE:
median 1.000, EsoF haircut bands (0.65/0.8/0.9/0.3) visible. NOTE: 28% upward tail
(recorded>base) = NEXT parity step (base mid-range param OR gold/gauge up-mult);
EsoF is haircut-only by design. Not yet wired into decision_engine (needs EsoF HZ
score plane + restart, held).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

prod/clean_arch/violet/modulation.py

@@ -0,0 +1,89 @@
+"""VIOLET V3.2: EsoF size-modulation layer — folds BLUE's SC/EsoF haircut.
+
+The base sizer (alpha_wrappers.VioletBetSizer) reproduces BLUE's cubic-convex
+conviction curve. But recorded BLUE `leverage` = base_sizer(vel_div) x EsoF_mult
+(the SC size gate) — the per-trade scatter the parity harness measured (V3d / the
+modulation-vs-underutilization finding). This module folds in that EXACT mult.
+
+FAITHFULNESS — replicates BLUE's `_apply_sc_entry_size_multiplier`
+(nautilus_event_trader.py:3307) step-for-step, in order, with the same atomicity:
+  1. mult = esof_size_mult_from_score(score)        (WRAP BLUE's canonical fn)
+  2. mult = max(0.0, min(1.0, mult))                (:3316 — HAIRCUT ONLY, [0,1])
+  3. if mult >= 0.999: return base UNCHANGED         (:3318 — near-1 = no-op)
+  4. effective_leverage  = round(base_leverage  * mult, 6)   (:3338)
+     effective_notional  = round(base_notional  * mult, 12)  (:3329)
+The score itself comes from the EsoF payload via esof_score_from_payload (WRAP);
+stale/missing → esof_size_mult_from_score(None) = the defensive fallback mult.
+
+Exchange-agnostic (L1): operates on conviction/notional fractions only.
+"""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+from typing import Any, Optional, Tuple
+
+from .alpha_wrappers import SizeDecision
+from .domain import typed
+
+_PROJECT_ROOT = Path(__file__).resolve().parents[3]
+
+
+def _import_esof_gate() -> Any:
+    """Import BLUE's esof_size_gate (same root-injection as blue_parity/alpha_wrappers)."""
+    try:
+        from nautilus_dolphin.nautilus import esof_size_gate  # type: ignore
+    except ImportError:
+        for p in (str(_PROJECT_ROOT / "nautilus_dolphin"), str(_PROJECT_ROOT)):
+            if p not in sys.path:
+                sys.path.insert(0, p)
+        sys.modules.pop("nautilus_dolphin", None)
+        from nautilus_dolphin.nautilus import esof_size_gate  # type: ignore
+    return esof_size_gate
+
+
+class VioletSizeModulation:
+    """BLUE's EsoF/SC size haircut, folded onto the base SizeDecision.
+
+    Wraps BLUE's canonical ``esof_size_mult_from_score`` / ``esof_score_from_payload``
+    (no reimplementation → exact ESOF_* constants + band mapping)."""
+
+    def __init__(self) -> None:
+        self._gate = _import_esof_gate()
+
+    # ── the EsoF score → mult (BLUE canonical fn + the [0,1] haircut clamp) ──────
+
+    def mult_for(self, score: Any) -> float:
+        """esof_size_mult_from_score(score) clamped to [0,1] (BLUE :3316).
+
+        ``score`` is accepted loosely (Any) to mirror BLUE's fn, which robustly
+        coerces/guards any score incl. None/stale → defensive fallback mult."""
+        mult = float(self._gate.esof_size_mult_from_score(score))
+        if mult != mult or mult in (float("inf"), float("-inf")):  # non-finite guard (:3314)
+            mult = 1.0
+        return max(0.0, min(1.0, mult))
+
+    def score_from_payload(self, payload: Optional[dict], **kw: Any) -> Optional[float]:
+        """Wrap esof_score_from_payload (HZ EsoF payload → fresh advisory score)."""
+        return self._gate.esof_score_from_payload(payload, **kw)
+
+    # ── apply to the base size, step-for-step as BLUE :3318-3338 ─────────────────
+
+    @typed
+    def apply(self, size: SizeDecision, score: Any) -> Tuple[SizeDecision, float]:
+        """Return (modulated_size, mult). Near-1 mult ⇒ base returned UNCHANGED."""
+        mult = self.mult_for(score)
+        if mult >= 0.999:                                     # BLUE :3318 — no-op
+            return size, mult
+        eff_leverage = round(size.conviction_leverage * mult, 6)        # :3338
+        eff_notional_fraction = round(size.notional_fraction * mult, 12)  # :3329 grain
+        modulated = SizeDecision(
+            fraction=size.fraction,
+            conviction_leverage=eff_leverage,
+            notional_fraction=eff_notional_fraction,
+            bucket_idx=size.bucket_idx,
+            strength_score=size.strength_score,
+            signal_bucket=size.signal_bucket,
+        )
+        return modulated, mult