[Merged] Low / Zero Credits Notification

This request was merged into a consolidated ticket.

Please follow the active ticket here: https://feedback.manyrequests.com/p/automatic-time-notification

Original request:

Automatically notify clients when their credit balance is running low or reaches zero.

Ideally, admins can set the threshold for the low-credit alert, for example at 5 credits remaining. This helps clients know when they need to purchase additional credits before submitting more requests.