perf: remove debug logging and optimize rolling window maintenance (+5.0%)

src/Managing.Application/Bots/TradingBotBase.cs

@@ -428,7 +428,16 @@ public class TradingBotBase : ITradingBot
             }
 
             // Check if we already have a position for this signal (in case it was added but not processed yet)
-            var existingPosition = Positions.Values.FirstOrDefault(p => p.SignalIdentifier == signal.Identifier);
+            // Optimized: Avoid LINQ FirstOrDefault overhead
+            Position existingPosition = null;
+            foreach (var pos in Positions.Values)
+            {
+                if (pos.SignalIdentifier == signal.Identifier)
+                {
+                    existingPosition = pos;
+                    break;
+                }
+            }
 
             if (existingPosition != null)
             {