Feature request: Kubernetes-native BoxLite deployment

Add a Kubernetes-native deployment mode where BoxLite workloads are hosted in a Kubernetes cluster and applications interact with them remotely through the BoxHub API.

A Kubernetes deployment via Helm/CRD would make it possible to use BoxLite as an internal platform runtime without requiring every application instance to have access to KVM, local storage, or the BoxLite runtime.

Conceptually

```
Application
|
| BoxHub API
v
+---------------------------+
| Kubernetes cluster |
| |
| BoxHub control plane |
| | |
| v |
| BoxLite runner pool |
| ├── Box A |
| ├── Box B |
| └── Box C |
+---------------------------+
```
Run the BoxHub API as a Kubernetes Deployment and deploy BoxLite runners on k8s nodes that provide `/dev/kvm`.

Start by reviewing the BoxHub API boundary and the proposed Helm/CRD deployment, then verify the Kubernetes runner requirements around /dev/kvm. Done would mean a Kubernetes-native BoxHub deployment can host BoxLite runners and let applications interact with workloads remotely through the BoxHub API.

Written by the indexing model from the issue text.