fix: ensure kubelet is enabled for kubeadm init node registration

Enable kubelet before kubeadm init and stop forcing kubelet out of wantedBy so kubeadm can reliably register the node during upload-config/kubelet. Also clear stale kubelet config files during remote prep to avoid restart-loop leftovers.

nixos/kubeadm/bootstrap/controller.py

@@ -212,6 +212,7 @@ class Controller:
         self.remote(ip, "sudo systemctl disable kubelet >/dev/null 2>&1 || true")
         self.remote(ip, "sudo systemctl mask kubelet >/dev/null 2>&1 || true")
         self.remote(ip, "sudo systemctl reset-failed kubelet >/dev/null 2>&1 || true")
+        self.remote(ip, "sudo rm -f /var/lib/kubelet/config.yaml /var/lib/kubelet/kubeadm-flags.env || true")
 
     def prepare_remote_space(self, ip):
         self.remote(ip, "sudo nix-collect-garbage -d || true")