Constant CAST_FP8E5M2_TO_BF16 

pub const CAST_FP8E5M2_TO_BF16: TosaFp8ToBfloat16Case;

Explicit FP8 E5M2 → BF16 CAST spanning signed zeros, subnormals, one, finite maximum, infinity, and NaN. All 256 byte encodings repeat four times across one XDNA conversion tile.