Undo an ads change within 24 hours (website only)

The id is an activity entry (change log id). Undo is a new change through the same pipeline: undoing a pause or a reduction raises spending, so it needs confirm=true (otherwise it waits for confirmation); a confirmed undo that raises the daily limit above twice its current amount needs a fresh second factor (403 owner_step_up_required). Undo never reverses charges already made. Website only: requests from the mobile apps are refused with 403 web_only_action. Behind LOPPEE_ADS_MANAGER: 404 while off, and with invite only for allowlisted businesses. Only the business's owner. Agent credentials are refused with 403 ads_owner_action_required.