CVE-2026-48029 libheif: heap OOB read in ImageItem_Grid::decode_grid_tile via irot-induced tile-coordinate underflow

libheif is a HEIF and AVIF file format decoder and encoder. Versions 1.19.0 through 1.21.2 have a heap OOB read in ImageItemGrid::decodegridtile via irot-induced tile-coordinate underflow. Version 1.22.0 fixes the issue...