feat: datetimes with timezones

repositories/deal.py

@@ -1,4 +1,4 @@
-from datetime import datetime
+from datetime import datetime, timezone
 from typing import Optional
 
 from sqlalchemy import select
@@ -25,7 +25,7 @@ class DealRepository(BaseRepository):
 
     async def create(self, data: CreateDealSchema) -> Deal:
         deal_data = data.model_dump()
-        deal_data["created_at"] = datetime.now()
+        deal_data["created_at"] = datetime.now(timezone.utc)
         deal = Deal(**deal_data)
         self.session.add(deal)
         await self.session.commit()