Per Andrey: the name must make it obvious this is a CALIBRATION file that has
to be preserved with the model (reliable_tiles are derived from it). New saves
use -POSE-RT-TILE-CALIB; the old -POSE-RT-MAXDXY is still read as a fallback,
so existing model dirs keep working. Tooltips/comments updated.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>