VIOLET V3e: shadow-decision journal + DDL (reject-at-source)

22_violet_decisions.sql (dolphin_violet.violet_decisions, DDL-first) +
shadow_journal.py: VioletDecisionJournal validates each actuated ShadowDecision
via DecisionRow (V-TYPES, allow_inf_nan=False) before the CH sink -- malformed
dies at source, never at the spool head. NEVER an order. DecisionRow field set ==
DDL columns (asserted). 4 tests pass. Launcher wiring + DARK soak = operator step.

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

prod/clickhouse/violet/22_violet_decisions.sql

@@ -0,0 +1,26 @@
+-- VIOLET V3e: shadow decision journal. One row per ACTUATED ShadowDecision the
+-- VioletDecisionEngine emits (the muted "what BLUE would do this scan"). NEVER an
+-- order — execution stays off behind the ObserveOnlyVenue guard. session_id is a
+-- boot-time UUID (mono_ns is meaningless across restarts without it).
+-- Apply via apply_violet_ddl.py (one statement per HTTP POST).
+
+CREATE TABLE IF NOT EXISTS dolphin_violet.violet_decisions
+(
+    `ts`                  DateTime64(3, 'UTC'),
+    `session_id`          String,
+    `scan_number`         UInt64,
+    `mono_ns`             UInt64,
+    `asset`               LowCardinality(String),
+    `side`                LowCardinality(String),
+    `vel_div`             Float64,
+    `fraction`            Float64,
+    `conviction_leverage` Float64,
+    `notional_fraction`   Float64,
+    `target_exposure`     Float64,
+    `ars_score`           Float64,
+    `bucket_idx`          UInt8,
+    `actuated`            UInt8
+)
+ENGINE = MergeTree
+ORDER BY (asset, ts)
+TTL toDate(ts) + toIntervalDay(180);