Fix realized pnl on backtest save + add tests (not all passing)

src/Managing.Common/Constants.cs

@@ -114,7 +114,7 @@ namespace Managing.Common
                 public const double AutoSwapAmount = 3;
 
                 // Fee Configuration
-                public const decimal UiFeeRate = 0.00075m; // 0.1% UI fee rate
+                public const decimal UiFeeRate = 0.0005m; // 0.05% UI fee rate
                 public const decimal GasFeePerTransaction = 0.15m; // $0.15 gas fee per transaction
             }