[claude] Fix pre-existing ruff lint errors blocking git hooks (#1247) (#1248)

src/infrastructure/router/cascade.py

@@ -16,7 +16,10 @@ from dataclasses import dataclass, field
 from datetime import UTC, datetime
 from enum import Enum
 from pathlib import Path
-from typing import Any
+from typing import TYPE_CHECKING, Any
+
+if TYPE_CHECKING:
+    from infrastructure.router.classifier import TaskComplexity
 
 from config import settings