Closed-position stats for a wallet

Aggregate over the wallet's CLOSED position lifecycles: count, average/min/max hold time, total and average realized PnL, win/loss counts, win rate, and the first/last close time (RFC 3339). Source: the latest 10,000 eligible rows for the wallet in position_lifecycles_full — closed perps only, excluding censored lifecycles that opened before the table's start. There is no time cutoff. The 10,000-position cap bounds work for very active wallets; totalPositions is therefore at most 10,000. losingPositions counts realized_pnl <= 0 (flat closes included), so winningPositions + losingPositions = totalPositions. winRate = winningPositions / totalPositions x 100. Coverage: this route previously aggregated the legacy closed_positions table, whose history reaches further back than the lifecycle table (which begins on 2026-08-31) but whose PnL was the unrealized snapshot at close rather than realized PnL, and whose exact per-position resolution could not complete within the request budget for wallets with tens of thousands of closed positions. totalPositions and firstClose can therefore be lower/later than before because lifecycle history is shorter and the newest 10,000-position cap may apply; PnL figures are now realized. Wallets with no eligible closed lifecycle return zero counts and omit firstClose/lastClose.