Add Notification Trigger for Top-Ranked Recommendations

[Xoshbin]

Is your feature request related to a problem? Please describe.
I’m looking for a way to proactively notify users when the most relevant recommendations are available to them. Currently, Gorse provides excellent recommendations, but there’s no built-in mechanism to alert users about high-priority or top-ranked content in real time.

Right now, I am using cron jobs to fetch the highest-ranked post for each user on an hourly basis and send notifications manually. While this works, it’s not efficient for real-time notifications and introduces delays, which can impact engagement, especially for time-sensitive content like trending posts or limited-time offers.

Describe the solution you'd like
I’d like to see a feature that triggers a notification when a post or item for a user reaches the highest rank in their recommendation list.

Key Aspects:
Triggering Logic:

Automatically detect when an item achieves the top rank (or top N ranks, configurable) for a user in their recommendation list.
Event/Notification Integration:

Emit events or provide webhook support to integrate with external notification systems, such as Firebase, Twilio, or email services.
Customization Options:

Allow developers to configure the trigger thresholds (e.g., top 1, top 3, etc.) or enable/disable this feature per use case.

Describe alternatives you've considered
Currently, I’m using cron jobs to fetch the highest-ranked post for each user on an hourly basis and send notifications. While this approach works, it’s not efficient for real-time updates. The delay introduced by the hourly schedule can reduce engagement, especially for time-sensitive content, and maintaining the cron job scripts adds extra complexity and overhead.

Additional context
This feature would be highly valuable for applications where user engagement is tied to delivering timely, relevant content. For example:

Social Media Applications: Notify users when trending posts or new content become highly relevant to them.
E-commerce Platforms: Alert users about the top-ranked products they might be interested in.
News Aggregators: Push notifications for breaking news articles that are most relevant to a user.

My English is not perfect, so I got some help from Chatgpt to write my feature request.