feat(market_scanner): 增强单个交易对信息日志记录，包含信号强度与价格

更新 `_log_single_symbol` 方法，改进日志记录内容，新增信号强度和价格信息，便于用户判断未触发交易的原因。同时，添加异常处理以确保信号强度的正确转换，提升系统的健壮性与可读性。

trading_system/market_scanner.py

@@ -330,25 +330,23 @@ class MarketScanner:
         return top_n
 
     def _log_single_symbol(self, index: int, symbol_info: Dict):
-        """打印单个交易对信息"""
+        """打印单个交易对信息（含信号强度，便于判断为何未触发交易）"""
         rsi_str = f"RSI:{symbol_info.get('rsi', 0):.1f}" if symbol_info.get('rsi') else "RSI:N/A"
         regime_str = symbol_info.get('marketRegime', 'unknown')
-        
         strength = symbol_info.get('signal_strength', symbol_info.get('signalScore', 0))
-        strength_str = f"信号:{strength}" if strength > 0 else ""
-        
+        try:
+            strength = int(strength) if strength is not None else 0
+        except (TypeError, ValueError):
+            strength = 0
+        strength_str = f"信号:{strength}"
         log_parts = [
             f"{index}. {symbol_info['symbol']}:",
             f"{symbol_info['changePercent']:.2f}%",
             rsi_str,
-            regime_str
+            regime_str,
+            strength_str,
+            f"价格: {symbol_info['price']:.4f}",
         ]
-        
-        if strength_str:
-            log_parts.append(strength_str)
-            
-        log_parts.append(f"价格: {symbol_info['price']:.4f}")
-        
         logger.info(" | ".join(log_parts))
 
     async def _prewarm_klines_for_scan(self, symbols: List[str], cfg: Optional[Dict] = None) -> None: