Validate Kustomize templates, overlays, and generated manifests before deployment. Use when:
(1) Modifying kustomization.yaml files in any GitOps repo,
(2) Creating new overlays or base configurations,
(3) Before merging PRs that touch kustomize directories,
(4) Debugging "kustomize build" failures or invalid manifests,
(5) User asks "validate my kustomize", "check overlays", "lint manifests",
(6) CI pre-merge validation for engineering-team-gitops, data-team-gitops, platform-team-gitops.
