Create Portal Token

curl -X POST "https://app.crovver.com/api/public/auth/portal-token" \
  -H "x-public-key: pk_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "externalTenantId": "workspace_123",
    "returnUrl": "https://app.com/settings/billing"
  }'

{
  "success": true,
  "data": {
    "token": "eyJhbGciOiJIUzI1NiJ9...",
    "expiresAt": "2025-01-01T00:10:00Z"
  },
  "meta": {
    "portalUrl": "https://portal.crovver.com/billing?token=eyJhbGci...",
    "expiresIn": 600
  }
}

{
  "success": false,
  "data": null,
  "error": {
    "message": "Tenant not found. Use the checkout flow to create a subscription first.",
    "code": "TENANT_NOT_FOUND"
  }
}