VIOLET V3e: enable shadow soak (faithful -0.02) + relaxable entry threshold

launch_dolphin_violet.py: _build_shadow reads DOLPHIN_VIOLET_ENTRY_VEL_DIV_THRESHOLD
(VIOLET-only gate relaxation for low-vol validation; logs RELAXED:not-parity-faithful).
supervisord.conf: DOLPHIN_VIOLET_DECISION_SHADOW=1 (faithful -0.02 default).
20-min validation soak PASSED: decisions journaled (sizer cubic curve reproduced
live), 0 bad rows, 0 orders, 0 errors. Findings for next: vel_div/asset pairing
parity (engine sizes IRP-picked asset w/ scan top-level vel_div), USDC-in-universe.

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

prod/launch_dolphin_violet.py

@@ -327,11 +327,17 @@ def _build_shadow():
     sess = uuid.uuid4().hex
     capital = float(os.environ.get("DOLPHIN_VIOLET_SHADOW_CAPITAL", "69000"))
     # engine defaults == live BLUE base curve (max_leverage 9.0, vel_div_threshold -0.02).
-    engine = VioletDecisionEngine()
+    # DOLPHIN_VIOLET_ENTRY_VEL_DIV_THRESHOLD relaxes the entry gate VIOLET-ONLY (e.g. to
+    # exercise the journal on a low-vol day). NOT BLUE-parity-faithful while relaxed.
+    thr = float(os.environ.get("DOLPHIN_VIOLET_ENTRY_VEL_DIV_THRESHOLD", "-0.02"))
+    relaxed = abs(thr - (-0.02)) > 1e-9
+    engine = VioletDecisionEngine(entry_vel_div_threshold=thr)
     journal = VioletDecisionJournal(sink=ch_put_violet, session_id=sess)
     LOGGER.warning(
-        "VIOLET DECISION SHADOW ON (session=%s ref_capital=%.0f) — journaling muted "
-        "decisions to dolphin_violet.violet_decisions; NO orders.", sess, capital,
+        "VIOLET DECISION SHADOW ON (session=%s ref_capital=%.0f entry_thr=%.4f%s) — "
+        "journaling muted decisions to dolphin_violet.violet_decisions; NO orders.",
+        sess, capital, thr,
+        " RELAXED:not-parity-faithful" if relaxed else "",
     )
     return {"engine": engine, "journal": journal, "capital": capital, "mono_ns": mono_ns}