- Both load and store atoms built from SAME tOtO_i (composition-tiled)
- Same Repetition(corr_tile_size=16) for both copies
- pv_done_bar synchronization between MMA and softmax warps
- acc_scale computed per kt iteration, used to rescale O in TMEM
- const_expr(n_kv_tiles > 1) guards for zero overhead at s_k=128
- New test: test_d15_in_kernel_rescale.py (s_k=128/256/384)
- Minimal roundtrip test: test_tmem_roundtrip_minimal.py