Update the selectable values for a custom field

This endpoint merges the provided selectable values with the existing values for a custom field.

Merge behavior:

• New values (values not present in the existing values) are added to the field
• Existing values (matching by value field) have their label updated and isArchived status set from the request
• Omitted values (existing values not included in the request) are marked as archived
• Metadata such as substitution tokens are preserved for existing values

The isArchived field defaults to false if not provided.

Requires the hiringProcessMetadataWrite permission.