Add the cluster-scoped ProviderHealth CRD

One operator-owned object per configured provider will carry the
periodic check result: a Ready condition, per-target verdicts with their
own transition times, and a ready/total count for kubectl get. There is
no spec; only a viewer role is shipped since the operator is the sole
writer. Written by hand (kubebuilder is not installed), registered in
the existing AddKnownTypes call rather than a second init().

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

config/rbac/kustomization.yaml

@@ -25,4 +25,7 @@ resources:
 - proxy_admin_role.yaml
 - proxy_editor_role.yaml
 - proxy_viewer_role.yaml
+# ProviderHealth objects are written only by the operator, so they get a
+# viewer role and nothing else.
+- providerhealth_viewer_role.yaml