chore: Update LynxChess.Lynx package reference to LynxChess.Lynx.Internal

src/Aiursoft.ChessServer/Aiursoft.ChessServer.csproj

@@ -15,6 +15,6 @@
     <PackageReference Include="Aiursoft.Scanner" Version="8.0.1" />
     <PackageReference Include="Aiursoft.WebTools" Version="8.0.21" />
     <PackageReference Include="Gera.Chess" Version="1.1.0" />
-    <PackageReference Include="LynxChess.Lynx" Version="1.5.1" />
+    <PackageReference Include="LynxChess.Lynx.Internal" Version="1.5.1" />
   </ItemGroup>
 </Project>

src/Aiursoft.ChessServer/Services/ChessEngine.cs

@@ -1,5 +1,4 @@
 using System.Threading.Channels;
-using Chess;
 using Lynx;
 using Lynx.Model;
 
@@ -21,13 +20,14 @@ public class ChessEngine
 
     public string GetBestMove(string fen)
     {
-        var board = ChessBoard.LoadFromFen(fen);
-        
         _engine.AdjustPosition($"position fen {fen}");
-        var moves = _engine.IDDFS(1, 10);
-        var bestMove = moves.Moves
-            .Select(t => t.ToEPDString())
-            .FirstOrDefault(t => board.IsValidMove(t));
-        return bestMove ?? moves.BestMove.ToEPDString();
+        var positionClone = new Position(_engine.Game.CurrentPosition);
+
+        var result = _engine.IDDFS(1, 10);
+        _engine.Game.ResetCurrentPositionToBeforeSearchState();
+
+        return result
+            .BestMove
+            .ToEPDString(positionClone);
     }
 }