fix(capabilities): read Python exit code directly

scripts/tests/test-capabilities.ps1

@@ -0,0 +1,11 @@
+[CmdletBinding()]
+param([switch]$Summary)
+$ErrorActionPreference = 'Stop'
+$root = Split-Path (Split-Path $PSScriptRoot -Parent) -Parent
+$content = Get-Content (Join-Path $root 'scripts/commands/check-capabilities.ps1') -Raw
+
+if ($content -match '(?s)\(& \$python --version.*?Select-Object.*?\).*?\$LASTEXITCODE') {
+    throw 'Python capability detection must not read $LASTEXITCODE after a pipeline.'
+}
+
+if ($Summary) { Write-Output 'Tests: PASS | capabilities' } else { Write-Output 'PASS capabilities: Python exit code is read without a pipeline' }