Accelerate acknowledged ladder orders

[jackhai9]

Summary

• remove the legacy fixed 520 ms delay after each ladder order
• require the current order API acknowledgement and native submit readiness before advancing
• revalidate live price and quantity after native post-submit cleanup
• add regression coverage for late toasts, aria-busy, and input cleanup races

Validation

• npm test (406/406)
• npm run build:binance-orderbook-trade
• npm run check:binance-orderbook-trade
• git diff --check
• npm run test:ui (60/60)