v1.0.0 — Institutional Grade HFT Engine

Production-ready release with:
- Singleton PolyClient + Binance WS (zero redundant connections)
- SIGINT/SIGTERM graceful shutdown with open order cancellation
- Semaphore rate limiter + 429 exponential backoff
- Zero-allocation hot path (ToPrimitive, Instant, cached Normal)
- Hysteresis circuit breaker, pending watchdog, strong sync reconciliation
- 10/10 unit tests, 0 warnings