Deduplicate the Gram-Schmidt basis construction that was copy-pasted
in decode_lcs_to_hsl, encode_hsl_to_lcs, and calibration.py. Extract
anchor hue values into a module-level constant to prevent silent
divergence. Also remove unnecessary tensor clone in _angle_to_hue and
use torch.empty instead of torch.zeros where all elements are overwritten.
Replace _hue_to_polygon_point with _hue_to_chroma_vector to fix
Type II and interpolated color intervention modes. The old function
interpolated raw 3D anchor positions (mixing lightness into chroma
directions) and ignored calibrated anchor angles. The new function
projects anchors onto the plane perpendicular to the achromatic axis
to get pure chroma radii, then interpolates radius and angle in the
same segment structure as _angle_to_hue for round-trip consistency.
Replace two calibration nodes with a single smart LCSLoadData that
fingerprints VAE weights (sha256 of first decoder weight) and
auto-manages cached calibration files as data/lcs_{fingerprint}.safetensors.
facok