fix: apply isort formatting to fix CI linting

Applied isort to properly sort all imports according to PEP8:
- Standard library imports first
- Third-party imports second
- Local imports last
- Alphabetical ordering within each group

All tests still passing after import reordering.

utils/token_utils.py

@@ -3,6 +3,7 @@ Token counting utilities
 """
 
 from typing import Tuple
+
 from config import MAX_CONTEXT_TOKENS