ActionView::Template::Error: undefined method 'each' for nil (ActionView::Template::Error)

## Error

```
undefined method 'each' for nil (NoMethodError)
```

## Stack trace

```
app/views/community/stories/index.html.haml:5
action_view/base.rb:263 in public_send
action_view/base.rb:263 in _run
action_view/template.rb:261 in block in ActionView::Template#render
active_support/notifications.rb:206 in block in ActiveSupport::Notifications.instrument
active_support/notifications/instrumenter.rb:58 in instrument
active_support/notifications.rb:206 in ActiveSupport::Notifications.instrument
action_view/template.rb:556 in instrument_render_template
action_view/template.rb:249 in render
action_view/renderer/template_renderer.rb:66 in block (2 levels) in ActionView::TemplateRenderer#render_template
```

## Tracking Details
- **Project**: exercism-rails
- **Sentry**: [ActionView::Template::Error: undefined method 'each' for nil (ActionView::Template::Error)](https://thalamus-ai.sentry.io/issues/101690127/)
- **Culprit**: Community::StoriesController#index
- **First seen:** Mar 8, 2026