feat: Enhance ClusterManager with dynamic scaling, restart policies, …

[jkyberneees]

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[Copilot]

Pull Request Overview

This PR enhances the ClusterManager with dynamic scaling capabilities, improved restart policies, and better lifecycle management. The changes add support for rolling restarts, exponential backoff with jitter, and configurable exit behavior for test environments.

• Added dynamic scaling methods (scaleTo, scaleUp, scaleDown) for runtime worker adjustment
• Implemented rolling restart strategy that spawns replacements before terminating old workers
• Enhanced restart policy with sliding window throttling and exponential backoff with jitter

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
src/interfaces/gateway.ts	Adds exitOnShutdown configuration option for embedded environments
src/cluster/cluster-manager.ts	Major enhancements including dynamic scaling, rolling restarts, and improved restart policies
test/cluster/fixtures/worker.ts	Minimal test worker script that responds to SIGTERM
test/cluster/cluster-manager.basic.test.ts	Basic functionality tests for startup and scaling operations
test/cluster/cluster-manager.restart-policy.test.ts	Tests for restart throttling and rolling restart behavior

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