List trending wallets

Returns wallets ranked by Polymarket weekly/monthly P&L (Polymarket-only discovery), with opaque page-cursor pagination. trending_pnl_usd and the by-PNL row order come from Polymarket's canonical leaderboard (data-api.polymarket.com/v1/leaderboard?timePeriod=week|month&orderBy=PNL), not a locally summed realized-leaf total. Each row also carries window volume, distinct markets, grade, hot-streak tier, and a shape-only daily P&L sparkline derived from the Polymarket user-pnl cumulative curve (per-day deltas; not guaranteed to sum to trending_pnl_usd). The underlying read model is warmed into Redis; a cold read returns 503 (warming, retry-after), never a 500 or a fabricated ranking. Polymarket-only: the read model filters platform = 'polymarket'.