GravityField is now the band term U(eps, inner, outer) (C4 smoothstep fade, closed form and a series for tau > 1).
WellTree is built once per Zone from the orbit tree: node terms, reach, support, the pruned Force/Potential walk and
PullAround (rails). Zone.GetHeight/GetForce/PeriodAround delegate to it; WellReference, _wellOn, _strengths,
Strength() and DrawAhead.Well are gone; GravityLowering and the shader template take the flat term list;
HeightExaggeration halves to 2.0491803.
Does not pass yet: Gravity.cginc is not regenerated and PotentialOwnerTests/OrbitsFromFieldTests still spell the old law.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
