nx_p256_scalar_mul_test.nx

nx_p256_scalar_mul_test.nx -- KAT for P-256 scalar multiplication. Verifies for small k values: - 0 * G = O - 1 * G = G - 2 * G = double(G) - 3 * G = G + 2G - 4 * G = double(2G) = via scalar_mul(4, G) - 256 * G = 8 doublings of G - aliasing: out aliases p in scalar_mul - 0 * O = O, k * O = O for various k Larger k values are exercised indirectly via the ECDSA verify KAT (queued for piece 4) -- 256-bit scalars take ~2-3s each in the slow form and would push smoke runtime past budget. expect_exit: 0 license_tier: ORIGINAL