Constant RAW_FUSED_RANK_LIMIT 

pub const RAW_FUSED_RANK_LIMIT: usize = 8; // 8usize

Rank up to which a fused loop nest is stored inline.

The stateless copy_scale_raw family and crate::CopyPlan fuse any rank: layouts whose fused rank is at most this limit replay from that inline storage, and higher fused ranks spill to storage bounded by their rank.

Replay is allocation-free for an original rank at most this limit. A higher original rank needs one transient scratch buffer even when the fused layout still fits inline, because fusion happens before the representation is chosen; the replay itself is still allocation-free in that case.