Feature request: Add notification channel filters by priority

[ig-quantum]

Currently, notification channels can filter alerts by severity only.

It would be useful to support filtering by priority as well. Priority is often a more actionable indicator for notification routing, allowing teams to decide which alerts require immediate attention and which can be handled through other channels or workflows.

For example, users could configure different notification channels based on priority:

Slack:     P1, P2
Telegram:  P1
Email:     P1, P2, P3

This would provide more flexibility for notification routing and allow users to build notification policies around the alert attributes that are most relevant to their workflows.

In some environments, priority is actively maintained while severity is rarely used, making priority-based filtering especially useful.

[Aidaho12]

Thanks for the suggestion. This use case makes sense, but priority-based routing is already covered by Notification Policies.

Notification Policy rules can match on alert priority and route matching events to selected notification channels, so adding a separate priority filter directly to channels would duplicate the same logic in two places.

What we may improve instead is the Notification Policy UI, for example by adding simple Priority and Severity selectors on top of the existing matcher system.

We’ll treat this primarily as a UX improvement rather than a new channel-level filtering feature.