ocean_fft

Transforms one axis of an ocean cascade's complex field in place, as one dispatch per axis: a workgroup per line runs every Stockham auto-sort radix-2 butterfly stage against workgroup-shared memory, so a 256-wide transform costs one dispatch rather than eight butterfly passes and needs no bit-reversal permutation. Supports grids up to 512 per side. The axis, direction and scale arrive through the bound plan buffer rather than a params: uniform, because same-frame dispatches are chained into one submission and a uniform rewritten between them would not be seen per-dispatch.