TypeError: Math.floor is not a function. (In 'Math.floor(e/50)', 'Math.floor' is 6.4)

## Error

```
Math.floor is not a function. (In 'Math.floor(e/50)', 'Math.floor' is 6.4)
```

## Stack trace

```
/beacon.min.js:1 in M
/beacon.min.js:1 in c
/beacon.min.js:1
/beacon.min.js:1
/beacon.min.js:1
../node_modules/@sentry/browser/src/helpers.ts:117 in sentryWrapped
```

## Tracking Details
- **Project**: exercism-js
- **Sentry**: [TypeError: Math.floor is not a function. (In 'Math.floor(e/50)', 'Math.floor' is 6.4)](https://thalamus-ai.sentry.io/issues/145230499/)
- **Culprit**: M(beacon)
- **First seen:** Sep 6, 2026

Start with the linked Sentry report and the `/beacon.min.js` stack trace, then trace the failing `Math.floor(e/50)` path back to its source in the exercism-js project. Verify what changes `Math.floor` to the reported numeric value and confirm that the browser path no longer reports this TypeError.

Written by the indexing model from the issue text.