Add Pod /resize subresource support for in-place vertical scaling

[cuppett]

Summary

Add first-class support for the Pod /resize subresource used by in-place vertical scaling.

Motivation

In-place Pod resize has been beta since Kubernetes 1.33 and received further scheduler-preemption and memory-backed-volume work in 1.37. Generic Pod attributes are insufficient because resize uses a distinct subresource.

Implementation

• Add an operation targeting PATCH /api/v1/namespaces/{namespace}/pods/{name}/resize.
• Support resource requests/limits payloads and common query parameters.
• Keep this separate from the existing WebSocket TTY resize channel used by exec/attach.

Acceptance Criteria

• A Pod can submit valid resize resource requests through the /resize subresource.
• Unsupported/disabled API, validation, and conflict responses surface as KubernetesAPIException with the server status code/payload.
• Unit tests cover URL, method, content type, payload, and query construction.
• Live-cluster integration tests cover successful behavior where the feature is available.
• Documentation explains Kubernetes version/feature-gate requirements.

Source

Identified by the Kubernetes 1.37 feature-gap review.