Function xqsm_tiled 

pub fn xqsm_tiled(
    local_field_ppm: &[f64],
    mask: &[u8],
    grid: &Grid,
    model_onnx: &[u8],
    cfg: &TileConfig,
    progress: impl FnMut(usize, usize),
) -> Result<Vec<f64>, OnnxError>

Memory-bounded xQSM via overlap-tiling — the same fully-convolutional net run patch-by- patch so peak memory is bounded by one patch (for 32-bit WASM, where the whole-volume xqsm overflows the 4 GB heap on clinical-size data). Results approximate whole-volume xQSM up to tile-boundary error; see crate::inversion::tiled.