feat(ops): track broker balance worker failure lifecycle and backoff

Co-authored-by: genichin <4282227+genichin@users.noreply.github.com>

tests/adapters/broker/test_kis.py

@@ -59,7 +59,8 @@ def test_account_scope_hash_separates_endpoint_and_application_identity():
         (403, "authorization_failed"),
         (422, "broker_rejected"),
         (429, "transport_failed"),
-        (500, "transport_failed"),
+        (500, "http_5xx"),
+        (504, "timeout"),
         (None, "broker_rejected"),
     ],
 )
@@ -350,8 +351,8 @@ def test_get_balance_fails_closed_on_later_transport_and_http_errors(monkeypatch
     request = httpx.Request("GET", "https://example.test/balance")
     response = httpx.Response(503, request=request)
     for failure, expected_code in [
-        (httpx.ConnectTimeout("unavailable"), "transport_failed"),
-        (httpx.HTTPStatusError("bad gateway", request=request, response=response), "transport_failed"),
+        (httpx.ConnectTimeout("unavailable"), "timeout"),
+        (httpx.HTTPStatusError("bad gateway", request=request, response=response), "http_5xx"),
     ]:
         broker, calls = _balance_broker(monkeypatch, [
             _BalanceResponse(_balance_payload([{"pdno": "005930", "hldg_qty": "2"}], fk="A", nk="1"), "F"),
@@ -407,6 +408,29 @@ def test_get_available_cash_uses_cash_only_amount(monkeypatch):
     assert b.get_available_cash() == 695_591
 
 
+@pytest.mark.parametrize(
+    ("failure", "expected_code"),
+    [
+        (httpx.ReadTimeout("timed out"), "timeout"),
+        (
+            httpx.HTTPStatusError(
+                "bad gateway",
+                request=httpx.Request("GET", "https://example.test"),
+                response=httpx.Response(502, request=httpx.Request("GET", "https://example.test")),
+            ),
+            "http_5xx",
+        ),
+    ],
+)
+def test_get_available_cash_classifies_timeout_and_http_5xx(monkeypatch, failure, expected_code):
+    b = KISBroker("12345678-01", app_key="k", app_secret="s", base_url=_MOCK_URL)
+    monkeypatch.setattr(b, "_headers", lambda _tr: {})
+    monkeypatch.setattr("trex_core.adapters.broker.kis.httpx.get", lambda *a, **kw: (_ for _ in ()).throw(failure))
+    with pytest.raises(BrokerBalanceError) as raised:
+        b.get_available_cash()
+    assert raised.value.code == expected_code
+
+
 def test_submit_transport_failure_blocks_automatic_duplicate(monkeypatch):
     b = KISBroker("12345678-01", app_key="k", app_secret="s", base_url=_MOCK_URL)
     monkeypatch.setattr(b, "_headers", lambda _tr: {})