* kube: URL-based local-proxy routing
* kube: drop wildcard local CA and SNI prefix
* kube: unexport kubeClusterKey
* kube: add tests for local-proxy path helpers
* kube: write error msg for old URL format
* kube: support both formats to preserve compatibility
* kube: drop misleading 'regenerate kubeconfig' error
* kube: drop in-place request mutation
* kube: fix tests for URL-based routing
* kube: drop legacy SNI fallback in local proxy