Validate native shared storage and document rollout

Description

Validate SMB fallback, native Secret projection, RBAC, Secret updates, metadata updates, projected-file latency, encryption-at-rest evidence handling, and cold-start metrics. Also validate a fully SMB-free configuration using native Secrets with an RWX PVC shared-data backend.

Document canary promotion, value pinning, rollback settings, go/no-go checks, and SMB CSI lifecycle considerations.

Definition of Done

• End-to-end tests verify the expected sensitive-data files and updates.
• Fully SMB-free mode leaves no NVCF-managed SMB server or SMB CSI PVC.
• The rollout guide includes rollback to either SMB backend.
• Validation evidence and known limitations are recorded without private environment details.