TypeError: undefined is not an object (evaluating 'e.user.handle')

## Error

```
undefined is not an object (evaluating 'e.user.handle')
```

## Stack trace

```
../app/javascript/components/impact/map.tsx:88 in MetricPointInner
../app/javascript/components/impact/map.tsx:160 in MetricPoint
../app/javascript/components/impact/map.tsx:180 in map_default
../node_modules/@sentry/react/src/errorboundary.tsx:101 in new ErrorBoundary
../node_modules/@tanstack/react-query/src/QueryClientProvider.tsx:30 in QueryClientProvider
```

## Tracking Details
- **Project**: exercism-js
- **Sentry**: [TypeError: undefined is not an object (evaluating 'e.user.handle')](https://thalamus-ai.sentry.io/issues/134283076/)
- **Culprit**: MetricPointInner(app/javascript/components/impact/map)
- **First seen:** Jul 14, 2026

Start by reading app/javascript/components/impact/map.tsx around lines 88, 160, and 180, then compare the failing MetricPoint data with the Sentry report. The issue is done when the map no longer throws when e.user is undefined, with the intended behavior for that metric point confirmed.

Written by the indexing model from the issue text.