Docker driver: recover profiles after the node container is removed #23798

Problem

TestMissingContainerUpgrade covers restarting a Docker-backed minikube profile after its node container has been removed while the persistent /var volume remains. Removing the container also removes non-persisted Kubernetes state such as /etc/kubernetes, leaving the profile in a state that the current startup path does not recover from reliably. The supported behavior and recovery path are unclear.

Reproduction

1. Start a Docker-driver profile: minikube start --driver=docker
2. Remove its node container outside minikube: docker rm -f minikube
3. Start the profile again: minikube start --driver=docker

The test scenario uses a named profile; substitute that profile's node container name in step 2.

Expected behavior

Determine whether minikube should recover the profile from the surviving data or reject the inconsistent state with a clear diagnostic and recovery instructions. Document the supported behavior and how users can recover.

Context

TestMissingContainerUpgrade is skipped in PR #23759 while this pre-existing behavior is investigated. The issue is not caused by the supported-version change in that PR.