Create a ChatGPT Ads chat card ad

Adds one paused chat card ad to an ad group that already exists: the image is downloaded, checked and uploaded, then the ad is created. Nothing delivers and nothing spends until the user resumes it. Use when: the user wants another creative in a structure they already have — a second headline to test, a replacement for a rejected ad. Get the ad group id from chatgpt_list_ad_groups. Do not use it to build a campaign from nothing: that is chatgpt_launch_ad. Do not invent copy, a destination or an image the user did not give; if any of the four is missing, ask. The limits are hard and checked before anything is created, so a rejection here costs nothing: the title must be 3–50 characters, the body at most 100, the destination an https URL, and the image square. Run chatgpt_validate_chat_card first if you want to check copy for free. Returns the new ad id, read back from the platform with its paused state and its review verdict. A new ad always starts in review; it delivers nothing until the platform approves it, so do not tell the user it is live until chatgpt_list_ads says approved.