nx_fieldfit_verified_r2_gate_t333.nx

nx_fieldfit_gate.nx -- THE FIELD-FIT MACHINERY (nx_fieldfit_lib) ON A SYNTHETIC ORACLE WITH A KNOWN ANSWER (anatomy AN17, 2026-09-19). The oracle is a point sphere of radius FG_R centred (FG_CX, FG_CY, FG_CZ), sampled on a 10-degree lattice; the field is a sphere whose centre and radius are stations 0..3 of a five-station vector, with station 4 a DECOY the field never reads and the live mask retires. Started from a wrong vector, the descent must recover the centre and the radius to FG_TOL mm, must leave the decoy untouched, and must not move from the true vector (a move accepted at the optimum is a broken accept rule). The fit file's prefix contract and the spatial hash are held to exact answers. NEG-CONTROL: the two-sided objective must charge a shrunken sphere MORE than the true one (a one-sided objective is gamed by deleting geometry; this is the tooth that cannot pass on one side). license_tier: ORIGINAL. No hw writes (Rule 26).