curl --request GET \
  --url https://api.altostrat.io/workspaces/{workspaceId}/billing-accounts/{billingAccountId}/payment-methods \
  --header 'Authorization: Bearer <token>'

{
  "data": [
    {
      "id": "pm_1Kb...",
      "type": "card",
      "is_default": true,
      "brand": "visa",
      "last4": "4242",
      "exp_month": 12,
      "exp_year": 2028,
      "name": "Jane Doe",
      "bank_name": "StripeBank"
    }
  ],
  "has_more": false
}