Merge remote-tracking branch 'origin/main'

src/summary_mcp/core/keyword_index.py

@@ -5,7 +5,9 @@ from __future__ import annotations
 
 import json
 from collections import Counter
-from datetime import UTC, date, datetime
+from datetime import date, datetime, timezone
+
+UTC = timezone.utc
 from pathlib import Path
 from typing import Iterable