feat: /trading-apps comparison table

[Flotapponnier]

Summary

• Replaces product grid + bench list with a unified comparison table
• 9 platforms as rows, 5 metric columns: 24h Volume, Unique Traders, Avg Trade, Fee Rate, App Rating
• Each column header links to the underlying bench page
• Best value per column highlighted in green, sorted by volume descending
• Fetches 5 snapshots in parallel (revalidate=60)