Atom engine — HelixNoise.createAtoms(...), regional handedness

The field is a sum of compactly-supported helical atoms placed by a spatial hash — broadband, infinite, and locally parameterized: here helicityField makes the left half right-handed (teal) and the right half left-handed (amber). Every atom is an exact curl, so the seam costs no divergence. Colour is the genuine helicity density u·ω, computed analytically.