feat: resolve and persist actual order venue

trex_core/application/execution.py

@@ -201,7 +201,11 @@ class ExecutionService:
                 )
             )
             if ack.accepted and ack.broker_order_id:
-                self._repo.mark_dispatched(slot.slot_id, ack.broker_order_id)
+                self._repo.mark_dispatched(
+                    slot.slot_id,
+                    ack.broker_order_id,
+                    venue=ack.venue,
+                )
                 r.dispatched += 1
                 if ack.reason and ack.reason.startswith("submit_outcome_unknown:"):
                     _log.warning(
@@ -643,6 +647,7 @@ class ExecutionService:
             fee=float(fs.fee),
             tax=float(fs.tax),
             executed_at=datetime.now(tz=timezone.utc),
+            venue=slot.venue,
         )
         self._ledger_outbox.enqueue(trade)
         r.ledger_enqueued += 1