Cumulative PnL curve for a bound wallet

Time-series of cumulative profit/loss (USD) for one wallet over the requested `window`. This is the same Profit/Loss curve a provider's own UI shows — Hyperliquid via `info portfolio.pnlHistory`, Polymarket via the official `user-pnl` series (registry-independent: marks even unregistered short-lived markets). Each point is `{ t (unix seconds), pnl }`, ascending. Cached ~60s with request coalescing. NOTE: this is PnL, not NAV — NAV(t) = cumulativeNetDeposits(t) + pnl(t).