Cost center access control and custom field select options

Five new endpoints are now available in the Perk API for managing cost centers and custom fields:

• PUT /cost_centers/{id}/access — set who can access a cost center: all users, specific users, or specific user groups
• PATCH /cost_centers/{id} — set company scoping on a cost center (the companies field was previously read-only)
• GET /custom-fields/{id}/select-options — retrieve select options for a select or multi-select custom field
• POST /custom-fields/{id}/select-options — add one or more options to a select or multi-select custom field
• POST /custom-fields/{id}/select-options/{id}/{archive_action} — archive or restore a select option

Previously, you could only configure cost center access and company scoping in the app. There was no way to manage custom field select options via API, meaning you needed to manual enter values in the app for any integration that needed to keep option lists in sync with an HR or ERP system.