Fix stdout/stderr deadlock in CmdHelper.RunCmdAndGetOutput

Read stdout and stderr concurrently to prevent pipe buffer deadlock.
The sequential ReadToEnd() calls caused a hang when child processes
(e.g. dotnet build) produced enough stderr output to fill the OS
pipe buffer (~4KB on Windows), since the parent blocked on stdout
while the child blocked on stderr.

Made-with: Cursor

framework/src/Volo.Abp.Cli.Core/Volo/Abp/Cli/Utils/CmdHelper.cs

@@ -1,7 +1,8 @@
-using System;
+using System;
 using System.Diagnostics;
 using System.IO;
 using System.Runtime.InteropServices;
+using System.Threading.Tasks;
 using Microsoft.Extensions.Options;
 using Volo.Abp.DependencyInjection;
 
@@ -137,14 +138,13 @@ public class CmdHelper : ICmdHelper, ITransientDependency
 
             process.Start();
 
-            using (var standardOutput = process.StandardOutput)
-            {
-                using (var standardError = process.StandardError)
-                {
-                    output = standardOutput.ReadToEnd();
-                    output += standardError.ReadToEnd();
-                }
-            }
+            var outputTask = process.StandardOutput.ReadToEndAsync();
+            var errorTask = process.StandardError.ReadToEndAsync();
+
+            output = Task.WhenAll(outputTask, errorTask).GetAwaiter().GetResult()
+                is { Length: 2 } results
+                ? results[0] + results[1]
+                : string.Empty;
 
             process.WaitForExit();