Build FoodRatings display component on detail page

## Goal
On the food detail page, render a `FoodRatings` component showing the average stars, a star row visualization, and the list of comments.

## Acceptance criteria
- [ ] Average displayed (e.g., "4.3 / 5 (12 reviews)")
- [ ] Star row visually represents the average
- [ ] Comment list shows each rating's stars + comment
- [ ] Empty state when there are no ratings yet

Start at the food detail page entry point and inspect how food data and ratings are currently loaded, along with any existing UI components for stars or comments. Implement the FoodRatings component so the average, star visualization, comment list, and empty state satisfy every acceptance criterion, then verify the detail page in each state.

Written by the indexing model from the issue text.