- Guard empty recipients in _handle_multi_threshold_max_budget_alert:
log warning and skip instead of falling through to old path error loop
- Widen max_budget_alert_emails type to Dict[str, Union[str, List[str]]]
to match _parse_email_list runtime behavior (accepts comma-separated strings)
- Pre-filter asyncio.create_task with min threshold check to avoid
unnecessary task allocation on every request when spend is below
all configured thresholds