Add RWX compatibility and quota guardrails

Description

Validate each selected RWX StorageClass with a disposable PVC and two short-lived pods scheduled on different nodes. Cache health per cluster and StorageClass, and invalidate it when relevant class, topology, probe, implementation, or expiry inputs change.

Support optional namespace ResourceQuota guardrails and warn when the selected StorageClass uses a Retain reclaim policy.

Definition of Done

• Tests cover successful cross-node read and write, scheduling failure, data mismatch, cleanup, and cache invalidation.
• ResourceQuota creation and denial are covered.
• Probe resources are isolated from application PVCs and labeled for cleanup.
• Errors distinguish provisioning, quota, and incompatible RWX behavior.