A Pod can only mount PVCs from its own namespace; the CronJob referenced the
minecraft-namespace backup PVC while being rendered under ControlNamespace, so
it could never schedule — live drill: FailedScheduling 'persistentvolumeclaim
felis-backups not found'. The reaper Role/RoleBinding were already
minecraft-scoped (the objects it touches live there), so the CronJob was the
odd one out. The minecraft felis-config replica (felis setup, backup Job fix)
supplies its config mount.