Get Specific Folder

Retrieves the full state of a single folder by its folderId. Returns all folder attributes — name, starred status, description, notes, creation and update timestamps, and the list of audienceId values contained in the folder. Use this endpoint to inspect a folder's contents before operating on its audiences, or to verify folder state after an update. Returns 200 with the folder resource. Returns 404 if no folder matches the provided folderId.