add state notification support in raft core

[somdoron]

No description provided.

[Copilot]

Pull Request Overview

This PR introduces state notification support to the Raft consensus implementation, allowing consumers to subscribe to leadership state changes. The implementation adds a new notification system that emits events when nodes step up to leadership, step down from leadership, or detect leader changes.

Key Changes:

• Added StateNotification ADT with three variants: SteppedUp, SteppedDown, and LeaderChanged
• Integrated a notification queue into the Raft core that publishes state transition events
• Exposed state notifications as a ZStream for consumption by clients

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
raft/src/main/scala/zio/raft/Types.scala	Defines the StateNotification sealed trait with case objects/classes for different state transition events
raft/src/main/scala/zio/raft/Raft.scala	Adds notification queue to Raft class, implements notification logic in state transition methods, and exposes stateNotifications stream

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[Copilot]

Pull Request Overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

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