Previous sweep used alpha=rank (scale=1.0) which at rank 128/256 drowned
base model priors — spectral flatness went from 0.013 (baseline) to 0.094.
This sweep tests alpha dramatically below rank across r16/r32/r128 to find
the scale where LoRA nudges rather than overwrites.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>