feat(customizations): add removal commands

scripts/commands/remove-credentials.ps1

@@ -0,0 +1,27 @@
+[CmdletBinding()]
+param(
+    [ValidateSet('Codex','Claude','Both')][string]$Client,
+    [string]$Key
+)
+$ErrorActionPreference = 'Stop'
+$root = Split-Path (Split-Path $PSScriptRoot -Parent) -Parent
+. (Join-Path $root 'scripts/lib/install-targets.ps1')
+$selectedClient = $Client
+$selectedKey = $Key
+. (Join-Path $root 'scripts/lib/credentials.ps1')
+$Client = $selectedClient
+$Key = $selectedKey
+
+if (-not $Client) { $Client = Read-InstallClient -Client $Client }
+if (-not $Key) { $Key = Read-Host 'Credential key to remove' }
+Assert-CredentialKey $Key
+
+foreach ($target in $(if ($Client -eq 'Both') { @('Codex', 'Claude') } else { @($Client) })) {
+    try {
+        Remove-ManagedCredential $target $Key
+        Write-Output "Credential removed for $($target.ToLowerInvariant())."
+    } catch [ComponentModel.Win32Exception] {
+        if ($_.Exception.NativeErrorCode -ne 1168) { throw }
+        Write-Output "Credential not found for $($target.ToLowerInvariant())."
+    }
+}