Fix missing Optional import in views_api.py

Added typing.Optional import that was missing after adding the
report endpoints with optional date parameters.

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Co-Authored-By: Claude <noreply@anthropic.com>

views_api.py

@@ -1,6 +1,7 @@
 from datetime import datetime
 from decimal import Decimal
 from http import HTTPStatus
+from typing import Optional
 
 from fastapi import APIRouter, Depends, HTTPException
 from loguru import logger