GravityField is the law of one well (logarithmic tail, softened core).
Zone.GetForce and GetHeight sum it over the bodies; GetNormal derives from
the force for ship tilt; Flow and Ship read GetForce. Well strength, core
radius and Roche limit are PlanetSettings curves of mass, height
exaggeration K one global. Deletes GravityAcceleration, GravityReferenceRate,
GravityStrength, the PowerPulse well, GetNormal's finite differences and
BodyData.GravityDepthExponent. Settings.asset carries the calibrated curves.
Tests: PotentialOwnerTests, the moon's moon placement, retired keys over every
BodyData type, a body-derived giant sweep. Not yet built or run (verify job
follows); this commit may not build.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
