feat: resolve and persist actual order venue

trex_core/adapters/persistence/sql/019_preserve_actual_order_venue.sql

@@ -0,0 +1,20 @@
+-- dcy-041 / GitHub #44: AUTO may exist while an intent is pending, but the
+-- actual submitted KRX/NXT value replaces it atomically with broker_order_id.
+ALTER TABLE daily_slot
+    DROP CONSTRAINT IF EXISTS daily_slot_venue_check;
+
+ALTER TABLE daily_slot
+    ADD CONSTRAINT daily_slot_venue_check
+    CHECK (venue IN ('AUTO', 'KRX', 'NXT', 'SOR'));
+
+-- Core keeps the actual venue in its durable ledger outbox. Portfolio Hub's
+-- HTTP schema is intentionally unchanged in this migration.
+ALTER TABLE ledger_outbox
+    ADD COLUMN IF NOT EXISTS venue TEXT NOT NULL DEFAULT 'KRX';
+
+ALTER TABLE ledger_outbox
+    DROP CONSTRAINT IF EXISTS ledger_outbox_venue_check;
+
+ALTER TABLE ledger_outbox
+    ADD CONSTRAINT ledger_outbox_venue_check
+    CHECK (venue IN ('AUTO', 'KRX', 'NXT', 'SOR'));