feat: apply rel-001 feedback cleanup

tests/test_v1.py

@@ -359,7 +359,7 @@ def _trade_payload(**overrides) -> dict:
 def _make_ledger_trade(**kwargs) -> LedgerTrade:
     defaults = dict(
         ledger_entry_id=1,
-        asset_id="005930",
+        portfolio_id="005930",
         order_id="ord-001",
         execution_id="exec-001",
         side="buy",
@@ -411,7 +411,7 @@ def test_v1_ledger_trade_created(monkeypatch) -> None:
     assert resp.status_code == 201
     body = resp.json()
     assert body["status"] == "new"
-    assert body["asset_id"] == "005930"
+    assert body["portfolio_id"] == "005930"
 
 
 def test_v1_ledger_trade_idempotent_same_payload(monkeypatch) -> None: