/api/backtest now annotates each replay trade with the live loop's realized
P&L for the same (session, symbol) and returns a live_split summary (taken vs
not-taken n/sumR/avgR). Page grows two summary cells, a Live P&L column with
an amber ≠ marker when sim and live disagree on a trade's sign, and a footer
caveat: minute-bar granularity + adverse fills flip individual rows — trust
aggregates, not rows. Read-only annotation; cached replay result unchanged.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
