Review sorting options exist (helpful, recent, rating)

Reviews rendered in a single fixed order force shoppers to read chronologically, which buries the most decision-useful content. Negative reviews discovered through sorting drive credibility; a catalog that shows only the oldest or newest feedback reads like curation and erodes trust. Sort controls also let shoppers self-serve the exact signal they need — recency for fast-changing products, helpfulness for depth, rating extremes for risk assessment — so conversion lifts on products with mixed reviews.

Add a sort control at components/ReviewSort.tsx emitting recent, helpful, highest-rating, and lowest-rating values, and wire the API to accept a sort query parameter that maps to an ORDER BY clause. Verify the displayed order actually changes on each selection:

const sortMap = {
  recent: { created_at: 'desc' },
  helpful: { helpful_votes: 'desc' },
  'highest-rating': { rating: 'desc' },
  'lowest-rating': { rating: 'asc' }
}