Upgrade ccxt from 4.4.8 to 4.5.40

Key improvements:
- 80-190% performance gains in utility functions
- New margin/futures WebSocket support for Binance
- Better liquidation and position tracking
- coincurve library for faster ECDSA signing
- New exchange support (Aster)

All Exchange methods verified working with new version.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

requirements.txt

@@ -4,7 +4,7 @@ config~=0.5.1
 PyYAML==6.0.2
 pandas==2.2.3
 passlib~=1.7.4
-ccxt==4.4.8
+ccxt==4.5.40
 flask-socketio~=5.4.1
 pytz==2024.2
 backtrader==1.9.78.123