[Request]: Add --mount option to container k8s create

### Feature or enhancement request details

Currently `container k8s create` does not support mounting host directories into the node container, unlike `container create` / `container run`.

Adding `--mount` support allows mounts to the cluster node (useful for sharing data, config or other files directly into the k8s node) same way as `container create` / `container run`.

**Example:**

```bash
container k8s create --name dev --mount type=virtiofs,source=/foo/bar,target=/data,readonly
```

### Code of Conduct

- [x] I agree to follow this project's Code of Conduct

Start with the implementation and argument handling for `container create` and `container run`, then compare them with the `container k8s create` entry point. Trace how their `--mount` values reach the container, add equivalent support for the Kubernetes node, and verify the example mount syntax works without changing existing behavior.

Written by the indexing model from the issue text.