blackout: enforce bounded oldest-drop queue policy on overflow (#371)

tests/test_blackout_manager.py

@@ -79,3 +79,51 @@ def test_requeued_intent_is_processed_next_non_blackout_cycle() -> None:
     manager.requeue(first_batch[0])
     second_batch = manager.pop_recovery_batch(outside_blackout)
     assert len(second_batch) == 1
+
+
+def test_queue_overflow_drops_oldest_and_keeps_latest() -> None:
+    manager = BlackoutOrderManager(
+        enabled=True,
+        windows=parse_blackout_windows_kst("23:30-00:10"),
+        max_queue_size=2,
+    )
+    first = QueuedOrderIntent(
+        market_code="KR",
+        exchange_code="KRX",
+        stock_code="000001",
+        order_type="BUY",
+        quantity=1,
+        price=100.0,
+        source="first",
+        queued_at=datetime.now(UTC),
+    )
+    second = QueuedOrderIntent(
+        market_code="KR",
+        exchange_code="KRX",
+        stock_code="000002",
+        order_type="BUY",
+        quantity=1,
+        price=101.0,
+        source="second",
+        queued_at=datetime.now(UTC),
+    )
+    third = QueuedOrderIntent(
+        market_code="KR",
+        exchange_code="KRX",
+        stock_code="000003",
+        order_type="SELL",
+        quantity=2,
+        price=102.0,
+        source="third",
+        queued_at=datetime.now(UTC),
+    )
+
+    assert manager.enqueue(first)
+    assert manager.enqueue(second)
+    assert manager.enqueue(third)
+    assert manager.pending_count == 2
+    assert manager.overflow_drop_count == 1
+
+    outside_blackout = datetime(2026, 1, 1, 15, 20, tzinfo=UTC)
+    batch = manager.pop_recovery_batch(outside_blackout)
+    assert [intent.stock_code for intent in batch] == ["000002", "000003"]

tests/test_main.py

@@ -9,6 +9,7 @@ import src.main as main_module
 from src.config import Settings
 from src.context.layer import ContextLayer
 from src.context.scheduler import ScheduleResult
+from src.core.blackout_manager import BlackoutOrderManager
 from src.core.order_policy import OrderPolicyRejected, get_session_info
 from src.core.risk_manager import CircuitBreakerTripped, FatFingerRejected
 from src.db import init_db, log_trade
@@ -33,6 +34,7 @@ from src.main import (
     _extract_held_qty_from_balance,
     _handle_market_close,
     _inject_staged_exit_features,
+    _maybe_queue_order_intent,
     _resolve_market_setting,
     _resolve_sell_qty_for_pnl,
     _retry_connection,
@@ -6529,6 +6531,40 @@ async def test_blackout_queues_order_and_skips_submission() -> None:
     blackout_manager.enqueue.assert_called_once()
 
 
+def test_blackout_queue_overflow_keeps_latest_intent() -> None:
+    manager = BlackoutOrderManager(enabled=True, windows=[], max_queue_size=1)
+    manager.in_blackout = lambda now=None: True  # type: ignore[method-assign]
+
+    market = MagicMock()
+    market.code = "KR"
+    market.exchange_code = "KRX"
+
+    with patch("src.main.BLACKOUT_ORDER_MANAGER", manager):
+        assert _maybe_queue_order_intent(
+            market=market,
+            stock_code="005930",
+            order_type="BUY",
+            quantity=1,
+            price=100.0,
+            source="test-first",
+        )
+        assert _maybe_queue_order_intent(
+            market=market,
+            stock_code="000660",
+            order_type="BUY",
+            quantity=2,
+            price=200.0,
+            source="test-second",
+        )
+
+    assert manager.pending_count == 1
+    assert manager.overflow_drop_count == 1
+    manager.in_blackout = lambda now=None: False  # type: ignore[method-assign]
+    batch = manager.pop_recovery_batch()
+    assert len(batch) == 1
+    assert batch[0].stock_code == "000660"
+
+
 @pytest.mark.asyncio
 async def test_process_blackout_recovery_executes_valid_intents() -> None:
     """Recovery must execute queued intents that pass revalidation."""