Simplify timeout handling to ensure finally block executes

Author: yotsuda

.github/workflows/cross-platform-test.yml

@@ -447,26 +447,13 @@ jobs:
           if ($task.Wait($TimeoutMs)) {
             return $task.Result
           } else {
-            # On timeout, dump both Proxy and background pwsh stderr for debugging
+            # On timeout, just dump Proxy stderr and throw
             Write-Host "=== Proxy stderr (timeout debug) ===" -ForegroundColor Red
             while ($process.StandardError.Peek() -ge 0) {
               Write-Host ([char]$process.StandardError.Read()) -NoNewline
             }
             Write-Host ""
-            
-            Write-Host "=== Background pwsh stderr (timeout debug) ===" -ForegroundColor Red
-            # Kill bgProcess first to flush stderr
-            if (-not $bgProcess.HasExited) {
-              $bgProcess.Kill()
-              $bgProcess.WaitForExit(3000)
-            }
-            if ($bgStderrTask.Wait(3000)) {
-              Write-Host $bgStderrTask.Result
-            } else {
-              Write-Host "(stderr read timeout)"
-            }
-            
-            throw "Timeout waiting for response"
+            throw "Timeout waiting for response after $TimeoutMs ms"
           }
         }