nx_p256_solinas_timing.nx

nx_p256_solinas_timing.nx -- honest FAST(Solinas) vs SLOW(bit-serial) timing for the P-256 field multiply used by TLS ECDSA cert verify. The Solinas fast reduction is ALREADY the production path (p256_field_mul); the bit-serial p256_field_mul_slow is the retained oracle == the "naive reduction" baseline. Timing both on the SAME workload quantifies the reduction speedup that Solinas already delivers. Seeds from a runtime clock and chains a=mul(a,b) (data-dependent) so the optimizer cannot const-fold the field arithmetic away. No correctness claim here -- see nx_p256_solinas_difftest.nx for the bit-identical proof. license_tier: ORIGINAL