feat: add bounded KIS account read recovery

tests/application/test_snapshot_scheduler.py

@@ -2,16 +2,13 @@
 from __future__ import annotations
 
 from datetime import datetime, timezone, timedelta
-from unittest.mock import MagicMock, call
-
-import pytest
+from unittest.mock import MagicMock
 
 from trex_core.adapters.broker.paper import PaperBroker
 from trex_core.adapters.portfolio.stub_read import StubPortfolioRead
 from trex_core.application.alarm_emitter import AlarmEmitter
 from trex_core.application.portfolio import (
     BrokerCredentialPayload,
-    PortfolioHubUnavailableError,
     PortfolioItem,
     SnapshotStore,
     TradingContext,
@@ -266,7 +263,6 @@ def test_entry_allowed_fixed_for_day_no_refetch(monkeypatch):
 def test_successful_credential_cached_for_day():
     """REQ-115 AC-3: 성공 후 그날 내 재fetch 없음 — 캐시 유지."""
     fetch_count = {"n": 0}
-    original_fetch = StubPortfolioRead.fetch_broker_credential
 
     class CountingStub(StubPortfolioRead):
         def fetch_broker_credential(self):