Add check_symbols.py for ETH perpetuals filtering and enhance backtester with size handling

- Introduced `check_symbols.py` to load and filter ETH perpetual markets from the OKX exchange using CCXT.
- Updated the backtester to normalize signals to a 5-tuple format, incorporating size management for trades.
- Enhanced portfolio functions to support variable size and leverage adjustments based on initial capital.
- Added a new method in `CryptoQuantClient` for chunked historical data fetching to avoid API limits.
- Improved market symbol normalization in `market.py` to handle different formats.
- Updated regime strategy parameters based on recent research findings for optimal performance.

engine/market.py

@@ -94,8 +94,20 @@ def get_ccxt_symbol(symbol: str, market_type: MarketType) -> str:
     """
     if market_type == MarketType.PERPETUAL:
         # OKX perpetual format: BTC/USDT:USDT
-        quote = symbol.split('/')[1] if '/' in symbol else 'USDT'
-        return f"{symbol}:{quote}"
+        if '/' in symbol:
+            base, quote = symbol.split('/')
+            return f"{symbol}:{quote}"
+        elif '-' in symbol:
+            base, quote = symbol.split('-')
+            return f"{base}/{quote}:{quote}"
+        else:
+            # Assume base is symbol, quote is USDT default
+            return f"{symbol}/USDT:USDT"
+            
+    # For spot, normalize dash to slash for CCXT
+    if '-' in symbol:
+        return symbol.replace('-', '/')
+        
     return symbol