chore: cleanup dead code + null safety + BalanceConfig fix

- Delete DadoSystem.cs (empty stub, replaced by DiceSystem)
- Delete dead OnPromotionSelected method from GameManager (caused double turn toggle if wired)
- PurgatoryManager: null checks on _campaignState before MarkPieceDead/MarkPieceRecovered
- BalanceConfig.LoadFromJSON: actually applies JSON via JsonUtility.FromJsonOverwrite

Assets/Game/Scripts/Data/BalanceConfig.cs

@@ -89,11 +89,8 @@ namespace AjedrezPurgatorio.Data
             try
             {
                 string json = File.ReadAllText(path);
-                // Note: Unity's JsonUtility doesn't support nested objects well
-                // For now, we'll use default values and parse manually if needed
-                // In production, consider using Newtonsoft.Json or similar
-
-                Debug.Log("[BalanceConfig] Loaded from JSON (using default values for now).");
+                JsonUtility.FromJsonOverwrite(json, this);
+                Debug.Log("[BalanceConfig] Loaded from JSON successfully.");
             }
             catch (Exception ex)
             {

Assets/Game/Scripts/Mono/DadoSystem.cs

@@ -1,16 +0,0 @@
-using UnityEngine;
-
-public class DadoSystem : MonoBehaviour
-{
-    // Start is called once before the first execution of Update after the MonoBehaviour is created
-    void Start()
-    {
-        
-    }
-
-    // Update is called once per frame
-    void Update()
-    {
-        
-    }
-}

Assets/Game/Scripts/Mono/DadoSystem.cs.meta

@@ -1,2 +0,0 @@
-fileFormatVersion: 2
-guid: a1180e41d60ca4380b1e79cbd6c16c8b

Assets/Game/Scripts/Mono/GameManager.cs

@@ -400,19 +400,6 @@ private GameObject GetPrefabForPromotion(PieceType type, bool isWhite)
         _ => null
     };
 }
-
-private void OnPromotionSelected(PieceType pieceType)
-{
-    // Este callback es llamado por PromotionUI
-    // La pieza ya está en el tablero, solo necesitamos promocionarla
-    Debug.Log($"Jugador eligió promover a {pieceType}");
-    
-    // Cambiar turno después de promoción
-    _whiteTurn = !_whiteTurn;
-    
-    // Disparar evento de cambio de turno
-    OnTurnChanged?.Invoke(_whiteTurn);
-}
     
     public void PromotePawn(Piece pawn)
     {

Assets/Game/Scripts/Mono/Purgatory/PurgatoryManager.cs

@@ -98,15 +98,13 @@ public class PurgatoryManager : MonoBehaviour
     
     private void OnPlayerDeclinesPurgatory(bool isQuotaExhausted = false)
     {
-        // Marcar pieza como perdida (no permanente a menos que sea cuota agotada)
-        if (isQuotaExhausted)
+        if (isQuotaExhausted && _campaignState != null)
         {
             _campaignState.MarkPieceDead(_currentCapturedPiece);
             Debug.Log($"[PurgatoryManager] {_currentCapturedPiece.characterName} muere permanentemente (cuota agotada).");
         }
         else
         {
-            // Solo removida del tablero actual
             Debug.Log($"[PurgatoryManager] {_currentCapturedPiece.characterName} perdida para este tablero.");
         }
         
@@ -153,15 +151,19 @@ public class PurgatoryManager : MonoBehaviour
     
     private void ProcessPurgatoryResult(PurgatoryWinner winner)
     {
+        if (_campaignState == null)
+        {
+            Debug.LogWarning("[PurgatoryManager] CampaignState no asignado. No se puede registrar resultado.");
+            return;
+        }
+        
         if (winner == PurgatoryWinner.Player)
         {
-            // Victoria: pieza recuperada
             _campaignState.MarkPieceRecovered(_currentCapturedPiece);
             Debug.Log($"[PurgatoryManager] ¡{_currentCapturedPiece.characterName} recuperada!");
         }
         else
         {
-            // Derrota: pieza muerta permanentemente
             _campaignState.MarkPieceDead(_currentCapturedPiece);
             Debug.Log($"[PurgatoryManager] {_currentCapturedPiece.characterName} ha muerto permanentemente.");
         }