Converting Apple Immersive (AIVU) for Pico headsets with correct geometry. A working AIVU-to-Pico pipeline that renders through Apple's own calibration mesh (not a generic fisheye model), outputs 360 equirect stereo SBS for ArborXR, with exact FFmpeg commands, API calls, the traps that scramble or squish the image, and honest quality limits. Tested on Pico 4 Enterprise and Pico 4 Ultra.