Push authoritative game state on every move

The move endpoint now returns the full resulting board state, and the
controller and CPU orchestrator broadcast it (plus captured pieces and a
ply version) over SignalR, so clients render from one payload instead of
re-fetching. Removes the client-driven hub relay.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

JoshHeaps.Net/Services/Implementations/ComputerMoveOrchestrator.cs

@@ -26,7 +26,7 @@ public sealed class ComputerMoveOrchestrator(
         var result = chessService.MakeMove(state, move);
 
         await chessHub.Clients.Group(state.GameId.ToString())
-            .SendAsync("ReceiveMoveUpdate", state.GameId.ToString(), move, result);
+            .SendAsync("ReceiveMoveUpdate", state.GameId.ToString(), move, result, state.ToDto());
 
         return (move, result);
     }