Get trader P&L time series

Returns a trader's daily P&L time series and pre-derived stats from the precomputed daily_pnl read model: entries (daily cumulative P&L), period stats (all/90d/30d/7d), monthly aggregation, per-year totals, and the drawdown series. Reads the refreshed read model, not a per-request equity replay. A resolved trader with no daily P&L returns an empty structured object (HTTP 200); an unknown address returns 404. Spans both providers wherever the read model has the trader's series.