Add logo padding pixels to history persistence

Co-authored-by: TheJoeFin <[email protected]>

Author: Copilot

Simple QR Code Maker/Models/HistoryItem.cs

@@ -42,6 +42,8 @@ public ErrorCorrectionLevel ErrorCorrection
     public string? LogoImagePath { get; set; }
 
     public double LogoSizePercentage { get; set; } = 15;
+    
+    public double LogoPaddingPixels { get; set; } = 4.0;
 
     public HistoryItem()
     {

Simple QR Code Maker/ViewModels/MainViewModel.cs

@@ -131,6 +131,7 @@ partial void OnSelectedHistoryItemChanged(HistoryItem? value)
         }
 
         LogoSizePercentage = value.LogoSizePercentage;
+        LogoPaddingPixels = value.LogoPaddingPixels;
 
         SelectedHistoryItem = null;
     }
@@ -855,6 +856,7 @@ public async Task SaveCurrentStateToHistory()
             ErrorCorrection = SelectedOption.ErrorCorrectionLevel,
             LogoImagePath = logoImagePath,
             LogoSizePercentage = LogoSizePercentage,
+            LogoPaddingPixels = LogoPaddingPixels,
         };
 
         HistoryItems.Remove(historyItem);