Address code review feedback

Co-authored-by: JusterZhu <11714536+JusterZhu@users.noreply.github.com>

Author: Copilot

src/Common/CsprojReader.cs

@@ -131,11 +131,22 @@ private static string FindCsprojFile(string directory)
             return string.Empty;
 
         var csprojFiles = Directory.GetFiles(directory, "*.csproj", SearchOption.TopDirectoryOnly);
-        return csprojFiles.FirstOrDefault() ?? string.Empty;
+        
+        if (csprojFiles.Length == 0)
+            return string.Empty;
+        
+        if (csprojFiles.Length > 1)
+        {
+            Trace.WriteLine($"Warning: Multiple .csproj files found in {directory}. Using the first one: {csprojFiles[0]}");
+        }
+        
+        return csprojFiles[0];
     }
 
     /// <summary>
     /// Find .exe file with matching name recursively
+    /// Note: Uses SearchOption.AllDirectories which may be slow for large directory trees.
+    /// This is acceptable as release directories are typically small.
     /// </summary>
     private static string FindExeFile(string directory, string baseName)
     {

src/ViewModels/PacketViewModel.cs

@@ -150,7 +150,7 @@ private async Task BuildPacketAction()
         try
         {
             // Validate required fields
-            if (!ValidateRequiredFields())
+            if (!await ValidateRequiredFields())
                 return;
 
             // Read configuration from .csproj
@@ -276,7 +276,7 @@ private void CopyDriverFiles(string sourceDir, string targetDir)
     /// <summary>
     /// Validate required fields
     /// </summary>
-    private bool ValidateRequiredFields()
+    private async Task<bool> ValidateRequiredFields()
     {
         var errors = new System.Collections.Generic.List<string>();
 
@@ -298,7 +298,7 @@ private bool ValidateRequiredFields()
         if (errors.Any())
         {
             var message = $"The following required fields must be filled:\n{string.Join(", ", errors)}";
-            MessageBox.ShowAsync(message, "Validation Error", Buttons.OK).Wait();
+            await MessageBox.ShowAsync(message, "Validation Error", Buttons.OK);
             return false;
         }
 
@@ -345,8 +345,8 @@ private async Task<string> CreateConfigInfoFile()
                 MainAppName = ConfigModel.MainAppName,
                 ClientVersion = ConfigModel.ClientVersion,
                 PacketName = ConfigModel.Name,
-                Format = ConfigModel.Format.Value,
-                Encoding = ConfigModel.Encoding.DisplayName
+                Format = ConfigModel.Format?.Value ?? string.Empty,
+                Encoding = ConfigModel.Encoding?.DisplayName ?? string.Empty
             };
 
             var json = JsonConvert.SerializeObject(configInfo, Formatting.Indented);