Add reproducible SUN360 distortion benchmark evidence

claim-5: add executed JPEG/blur/noise/resize robustness + 32-64 bit capacity experiment (degree>16 negative control collapses)

Reproduce [2] embedding in degrees 6/8/14 + [3] rotation robustness: power spectrum exactly invariant (2.8e-14), TRIAD 100% vs baseline 50.5% under rotation