SyntaxError: Failed to execute 'appendChild' on 'Node': Unexpected token 'export'

## Error

```
Failed to execute 'appendChild' on 'Node': Unexpected token 'export'
```

## Stack trace

```
:1
:1
```

## Tracking Details
- **Project**: exercism-js
- **Sentry**: [SyntaxError: Failed to execute 'appendChild' on 'Node': Unexpected token 'export'](https://thalamus-ai.sentry.io/issues/144707318/)
- **Culprit**: ?()
- **First seen:** Sep 3, 2026

Start with the linked Sentry event and its stack trace, then trace the exercism-js code path that creates or appends the failing script. Confirm the browser no longer reports the Unexpected token 'export' error and add or update a regression test if the affected entry point has one.

Written by the indexing model from the issue text.