SecurityError: Blocked a frame with origin "https://exercism.org" from accessing a cross-origin frame. Protocols, domains, and ports must match.

## Error

```
Blocked a frame with origin "https://exercism.org" from accessing a cross-origin frame. Protocols, domains, and ports must match.
```

## Stack trace

```
/tracks/python/exercises/two-bucket:333 in c
```

## Tracking Details
- **Project**: exercism-js
- **Sentry**: [SecurityError: Blocked a frame with origin "https://exercism.org" from accessing a cross-origin frame. Protocols, domains, and ports must match.](https://thalamus-ai.sentry.io/issues/143563200/)
- **Culprit**: c(tracks/python/exercises/two-bucket)
- **First seen:** Aug 29, 2026

Start with the linked Sentry report and the stack trace at /tracks/python/exercises/two-bucket:333 in exercism-js. Investigate the cross-origin frame access involving https://exercism.org; done means the SecurityError no longer occurs for this exercise path, with an appropriate regression check if the project provides one.

Written by the indexing model from the issue text.