Replay mode: Portfolio.ClosedPnL always returns 0

TradingManager.Portfolio.ClosedPnL always returns 0 during Market Replay — OnPortfolioChanged never fires at all in replay mode. The only workaround is to regex-parse position.ToString() to extract the closed P&L string, which is fragile and undocumented.

Request: make Portfolio.ClosedPnL (and OnPortfolioChanged) work correctly in replay mode, the same as in live/paper trading. Strategy developers rely on closed P&L to enforce daily loss limits, profit goals, and session resets — none of these work in replay without this fix, making replay useless for strategy validation.