nx_geo_distance.nx

nx_geo_distance.nx -- LIB: GEO-003 geodesic DISTANCE in meters (equirectangular). Hardware-up: REUSES the sovereign CORDIC cos (fx.nx, Q16.16 fixed-point -- no reinvention) for the mean-latitude longitude-compression, REUSES nx_isqrt for the magnitude, and keeps the lat/lon deltas as INTEGER microdegrees (a single microdegree in radians would underflow Q16.16, so we do NOT convert the deltas -- only the mean latitude, a full angle, goes through cos). Pure integer/fixed-point -> deterministic distance (the exceed angle vs float distance libs). Accuracy: equirectangular is exact-direction and ~exact for local/regional spans; error grows to ~0.5% only at continental scale (haversine is the precision refinement, GEO-003b). Good for nearest-queries, true-meters radius fences, and routing edge weights. license_tier: ORIGINAL