[juniemariam]

Description

Adds optional horizontal autoscaling configuration for the Admission service. This introduces an autoscaling configuration with:

• enabled
• maxReplicas
• targetCPUUtilizationPercentage
• targetInFlightRequests

The autoscaling configuration remains unset by default, preserving the existing Admission configuration behavior.

This is the API portion of the Admission autoscaling work in KAI-Scheduler#2489.

Related Issues

Related to KAI-Scheduler#901
Implementation: KAI-Scheduler#2489

Checklist

Note: Ensure your PR title follows the Conventional Commits format (e.g., feat(scheduler): add new feature)

• Self-reviewed
• Added/updated tests (if needed)
• Updated documentation (if needed)
• Added a changelog fragment via make changelog (or applied the skip-changelog label). Do not edit CHANGELOG.md directly — pending fragments are folded into it at release time.

Breaking Changes

None. The new autoscaling configuration is optional and remains unset by default.

Additional Notes

Generated CRD and deepcopy changes are included.

Validation performed:

• make generate
• make manifests
• make validate
• make test
• go test ./kai/v1/admission/...
• git diff --check