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/test_violet_modulation.py

@@ -0,0 +1,97 @@
+"""V3.2: EsoF size-modulation — exact replication of BLUE's SC haircut (profuse)."""
+
+from __future__ import annotations
+
+import math
+import sys
+
+sys.path.insert(0, "/mnt/dolphinng5_predict")
+
+import pytest
+from hypothesis import given, settings, strategies as st
+
+from prod.clean_arch.violet.alpha_wrappers import SizeDecision, VioletBetSizer
+from prod.clean_arch.violet.modulation import VioletSizeModulation
+
+MOD = VioletSizeModulation()
+G = MOD._gate
+
+
+def _base(vel_div: float = -0.20) -> SizeDecision:
+    return VioletBetSizer(base_fraction=0.20, min_leverage=0.5,
+                          max_leverage=9.0).calculate(capital=69_000.0, vel_div=vel_div)
+
+
+# ── band mapping reproduces BLUE exactly (drift-guarded against live constants) ─
+
+def test_band_values_match_blue_constants():
+    assert MOD.mult_for(0.0) == pytest.approx(G.ESOF_NEUTRAL_CORE_MULT)      # neutral core
+    assert MOD.mult_for(-0.5) == pytest.approx(G.ESOF_UNFAVORABLE_CORE_MULT)  # deepest cut
+    assert MOD.mult_for(None) == pytest.approx(
+        min(1.0, max(0.0, G.ESOF_STALE_FALLBACK_MULT)))                       # stale fallback
+    assert MOD.mult_for(0.5) == pytest.approx(1.0)                            # full size
+    assert MOD.mult_for(-0.15) == pytest.approx(1.0)                          # mild-neg full
+
+
+def test_mult_equals_wrapped_blue_fn_clamped():
+    # mult_for == clamp(esof_size_mult_from_score, 0, 1) for a grid of scores.
+    for sc in [0.3, 0.05, 0.0, -0.03, -0.07, -0.2, -0.25, -0.3, -1.0, None]:
+        expect = max(0.0, min(1.0, float(G.esof_size_mult_from_score(sc))))
+        assert MOD.mult_for(sc) == pytest.approx(expect)
+
+
+# ── haircut-only [0,1] clamp (BLUE :3316) ──────────────────────────────────────
+
+@given(score=st.one_of(st.none(),
+                       st.floats(min_value=-5.0, max_value=5.0, allow_nan=False,
+                                 allow_infinity=False)))
+@settings(max_examples=120, deadline=None)
+def test_mult_always_in_unit_interval(score):
+    assert 0.0 <= MOD.mult_for(score) <= 1.0
+
+
+def test_nonfinite_score_is_safe():
+    for bad in (float("nan"), float("inf"), float("-inf")):
+        assert 0.0 <= MOD.mult_for(bad) <= 1.0
+
+
+# ── apply: near-1 = no-op; haircut scales with exact rounding (BLUE :3318-3338) ─
+
+def test_near_one_mult_returns_base_unchanged():
+    base = _base()
+    mod, mult = MOD.apply(base, 0.5)         # full-size band -> mult 1.0
+    assert mult >= 0.999
+    assert mod is base or mod.conviction_leverage == base.conviction_leverage
+
+
+def test_haircut_scales_with_blue_rounding():
+    base = _base()                           # conviction 9.0
+    mod, mult = MOD.apply(base, 0.0)         # neutral core -> mult 0.8
+    assert mult == pytest.approx(0.8)
+    assert mod.conviction_leverage == round(base.conviction_leverage * mult, 6)
+    assert mod.notional_fraction == round(base.notional_fraction * mult, 12)
+    # haircut ⇒ strictly smaller size
+    assert mod.conviction_leverage < base.conviction_leverage
+    assert mod.notional_fraction < base.notional_fraction
+
+
+def test_apply_preserves_fraction_bucket_signal():
+    base = _base()
+    mod, _ = MOD.apply(base, -0.5)           # deep haircut
+    assert mod.fraction == base.fraction     # only size/leverage scale, not fraction
+    assert mod.bucket_idx == base.bucket_idx
+    assert mod.signal_bucket == base.signal_bucket
+    assert isinstance(mod, SizeDecision)
+
+
+# ── property: modulated size never exceeds base (haircut-only) and stays finite ─
+
+@given(vel_div=st.floats(min_value=-0.5, max_value=-0.021, allow_nan=False),
+       score=st.one_of(st.none(), st.floats(min_value=-1.0, max_value=1.0, allow_nan=False)))
+@settings(max_examples=80, deadline=None)
+def test_modulated_never_exceeds_base(vel_div, score):
+    base = _base(vel_div)
+    mod, mult = MOD.apply(base, score)
+    assert mod.conviction_leverage <= base.conviction_leverage + 1e-9
+    assert mod.notional_fraction <= base.notional_fraction + 1e-9
+    assert math.isfinite(mod.conviction_leverage) and mod.conviction_leverage >= 0.0