ReferenceError: mainWorldSdk is not defined

## Error

```
mainWorldSdk is not defined
```

## Stack trace

```
:1
:1
```

## Tracking Details
- **Project**: exercism-js
- **Sentry**: [ReferenceError: mainWorldSdk is not defined](https://thalamus-ai.sentry.io/issues/142779880/)
- **Culprit**: ?()
- **First seen:** Aug 25, 2026

Start with the linked Sentry report for the exercism-js project; the issue names no source file, test, or entry point. Trace the anonymous execution that produces the ReferenceError, then verify that the error no longer occurs in the affected flow.

Written by the indexing model from the issue text.