nx_p256_point_add_test.nx

nx_p256_point_add_test.nx -- KAT for P-256 Jacobian point addition. Verifies: - G + O = G (infinity identity) - O + G = G (commutative identity) - O + O = O (infinity-only) - G + G = 2G (matches point_double(G)) - G + (-G) = O (additive inverse) - G + 2G is on curve, != G, != 2G, != O - (G + 2G) + G = 4G (cross-check: 4G also = double(2G)) - 2G + G = G + 2G (commutativity) - (G + 2G) + G = G + (2G + G) (associativity spot-check) - aliasing: out aliases p1, out aliases p2, all aliases expect_exit: 0 license_tier: ORIGINAL