Round 32 blitz: qsa_flash sp[4] 3->1 barrier & ko[j] offset + unroll (-4.0..-5.5% / -6.1 ms in kprof), mm_gu3 T_IQ2_S half4 HS store (-9.0 ms in kprof -> 3175.3 ms / 624.5 tok/s GPU prefill!), deq uint2 grid loads + deq_iq_packed (-> 408.75 tok/s prefill & 42.16 tok/s decode!)