AEG-X-004: align shadow run queued status contract

db/migrations/0032_shadow_run_queued_status_contract.sql

@@ -0,0 +1,31 @@
+-- AEG-X-004: align shadow_run status constraint with the existing Queued application state.
+-- Prior migrations are immutable; this is an append-only correction migration.
+DO $$
+DECLARE
+    shadow_run_oid oid := 'model_operations.shadow_run'::regclass;
+BEGIN
+    IF shadow_run_oid IS NULL THEN
+        RAISE EXCEPTION 'model_operations.shadow_run must exist before 0032';
+    END IF;
+
+    IF EXISTS (
+        SELECT 1
+        FROM pg_constraint
+        WHERE conrelid = shadow_run_oid
+          AND conname = 'check_status'
+    ) THEN
+        ALTER TABLE model_operations.shadow_run DROP CONSTRAINT check_status;
+    END IF;
+
+    IF NOT EXISTS (
+        SELECT 1
+        FROM pg_constraint
+        WHERE conrelid = shadow_run_oid
+          AND conname = 'check_status'
+    ) THEN
+        ALTER TABLE model_operations.shadow_run
+            ADD CONSTRAINT check_status CHECK (
+                status IN ('Pending', 'Queued', 'DataBackfill', 'Replay', 'EvaluationComplete', 'Failed')
+            );
+    END IF;
+END $$;