Annotate an image with detections using supervision's annotators (box, round_box, box_corner, circle, dot, ellipse, triangle, label, color, mask, polygon, halo, background_overlay, blur, pixelate, percentage_bar), applied in order. Input: base64 image up to 4 megapixels, up to 500 detections with xyxy pixel boxes and optional class_id, confidence, ASCII label, polygon. Returns the annotated image (base64 PNG or JPEG), size and counts per class.