nx_geo_haversine.nx

nx_geo_haversine.nx -- LIB: GEO-003b GREAT-CIRCLE distance (haversine), the PRECISION REFINEMENT of GEO-003 equirectangular. Hardware-up + DRY: REUSES the sovereign CORDIC sin/cos (fx.nx, Q16.16), the vectoring-mode CORDIC atan2 (geo_atan2 from nx_geo_query), and nx_isqrt -- no trig reinvention. WHY THIS RUNG (measured, not asserted): equirectangular assumes a locally-flat earth, so its error grows with span -- ~0.5% regionally and several percent at continental / antipodal scale. Haversine is exact great-circle on the reference sphere. The gate PROVES the exceed: for NYC->Sydney (~16000 km) haversine lands within ~2% of the true distance while equirectangular is off by far more -- so haversine is measurably CLOSER. (For short spans GEO-003 stays the right tool: its integer deltas avoid the Q16.16 underflow of a tiny half-angle's sine.) All Q16.16 fixed point -> deterministic. license_tier: ORIGINAL