[feature] Debounce Notifications Configuration

**Version and OS**
v0.55.8 linux/docker

**Is your feature request related to a problem? Please describe.**
I'm getting repeated notifications presumably because the item keeps changing in stock / out of stock status.

**Describe the solution you'd like**
I would like to be able to configure notification rate limits to limit notification triggers for this use case to one per day. For my use case, I just want one notification when the item becomes available.

**Describe the use-case and give concrete real-world examples**
Something like this maybe?

**Additional context**
N/A

No files or tests are named. Start by tracing the notification trigger flow and locating the existing notification configuration, then determine where repeated in-stock/out-of-stock changes are handled. Done should mean users can configure a notification limit such as one per day and receive one notification when an item becomes available, with tests covering repeated status changes.

Written by the indexing model from the issue text.