Proposal: Add BoxLite integration/use-case entry (optional sandbox path)

## Summary

Could we add a **BoxLite integration/use-case entry** as an optional sandbox path?

This is a docs/ecosystem request, not a core architecture replacement.

## Why

- Useful for users who want an optional micro-VM sandbox mode.
- Keeps current project behavior unchanged.
- Improves discoverability of secure runtime options.

## Tiny example (Node.js)

```ts
import { SimpleBox } from '@boxlite-ai/boxlite';

async function main() {
const box = new SimpleBox({ image: 'alpine:latest', autoRemove: true });
try {
const result = await box.exec('echo', 'hello');
console.log(result.stdout);
const m = await box.metrics();
console.log(`totalCreateDurationMs=${m.totalCreateDurationMs}`);
} finally {
await box.stop();
}
}

main();
```

Warm startup is typically under 200ms; cold starts can be higher depending on image/cache state.

## Suggested scope

1. Add a BoxLite integration/use-case section (or skill entry).
2. Include compatibility notes and known limits.
3. Include quick validation steps.