Added unrealized_pnl field to PosFlat (offset 24, 24→28 bytes).
Computed every step in both fill kernels (order_match + resting_orders)
as (mid - vwap_entry) × direction × |lots|. Zeroed when flat.
This gives Q real-time visibility into open-position drawdown through
the trade_context features. The confidence gate's margin floor now
checks total equity (realized + unrealized) instead of just realized.
Units: price-units × lots (same as realized_pnl). USD = value × $50.
14 files updated: struct def (Rust + CUDA), both fill kernels,
margin floor consumer, layout docs in 6 kernels, tests.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
f9a83a03d0