Patch an existing candidate's profile fields. Only the keys included in the request body are modified; omitted keys are left untouched. Array fields (phone_numbers, addresses, email_addresses, website_addresses, social_media_addresses, tags, linked_user_ids, custom_fields) replace the existing collection wholesale — send the full desired list, not a delta. Setting is_private to true restricts the candidate to users with View Private Candidates access.