fix: close broker uncertainty audit gaps

tests/adapters/broker/test_kis.py

@@ -11,7 +11,7 @@ import os
 import httpx
 import pytest
 
-from trex_core.adapters.broker.kis import KISBroker
+from trex_core.adapters.broker.kis import KISBroker, _balance_http_error_code
 from trex_core.application.broker_port import (
     BrokerBalanceError,
     CancelState,
@@ -31,6 +31,41 @@ def test_account_split_and_mock_tr_ids():
     assert "12345678" not in b.account_scope_hash()
 
 
+def test_account_scope_hash_separates_endpoint_and_application_identity():
+    mock_a = KISBroker(
+        "12345678-01", app_key="app-a", app_secret="s", base_url=_MOCK_URL
+    )
+    mock_b = KISBroker(
+        "12345678-01", app_key="app-b", app_secret="s", base_url=_MOCK_URL
+    )
+    live_a = KISBroker(
+        "12345678-01",
+        app_key="app-a",
+        app_secret="s",
+        base_url="https://openapi.koreainvestment.com:9443",
+        allow_live=True,
+    )
+
+    assert len({mock_a.account_scope_hash(), mock_b.account_scope_hash(),
+                live_a.account_scope_hash()}) == 3
+
+
+@pytest.mark.parametrize(
+    ("status", "code"),
+    [
+        (400, "broker_rejected"),
+        (401, "authentication_failed"),
+        (403, "authorization_failed"),
+        (422, "broker_rejected"),
+        (429, "transport_failed"),
+        (500, "transport_failed"),
+        (None, "broker_rejected"),
+    ],
+)
+def test_balance_http_status_classification(status, code):
+    assert _balance_http_error_code(status) == code
+
+
 def test_live_base_url_requires_allow_live():
     with pytest.raises(RuntimeError):
         KISBroker(