fix: preserve sell event routing owner

tests/domain/slot/test_service_sell.py

@@ -34,7 +34,7 @@ def _holding_slot(service, repo):
     slot = _inactive_slot(repo)
     pending = service.transit_slot(
         slot.slot_id, SlotState.INACTIVE, SlotState.PENDING_BUY,
-        reason="buy", actor="test", symbol="005930",
+        reason="buy", actor="test", symbol="005930", strategy_id="BUY-A",
     )
     return service.transit_slot(
         pending.slot_id, SlotState.PENDING_BUY, SlotState.HOLDING,
@@ -49,6 +49,7 @@ class TestSell:
         service.sell(holding.slot_id, actor="safety-sell", reason="stop_loss")
         updated = repo.fetch_slot(holding.slot_id)
         assert updated.status is SlotState.PENDING_SELL
+        assert updated.sell_strategy_id == "BUY-A"
 
     def test_sell_records_transition_log(self, service, repo):
         """sell() appends a transition log entry."""