feat: datetimes with timezones

models/mixins.py

@@ -1,5 +1,6 @@
 from datetime import datetime
 
+from sqlalchemy import DateTime
 from sqlalchemy.orm import Mapped, mapped_column
 
 
@@ -15,4 +16,6 @@ class SoftDeleteMixin:
 
 
 class CreatedAtMixin:
-    created_at: Mapped[datetime] = mapped_column(nullable=False)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False
+    )