// Written for Graviola by Joe Birr-Pixton, 2026.
// SPDX-License-Identifier: Apache-2.0 OR ISC OR MIT-0
/// This does `SampleNTT()` for MLKEM768, yielding 8 polynomials worth of coefficients.
///
/// `inputs` are eight pre-formatted SHAKE inputs (already containing the domain separation bits.
///
/// `outputs` are where to write the coefficients.
///
/// `fallback_fn` is a complete fallback implementation of the whole function, reading `inputs` and
/// writing `outputs`. It does not require `tail_fn`.
///
/// `tail_fn` takes a keccak state (which requires an immedate permutation prior to use) and a set
/// of "tail" coefficients which need to be filled via sampling the SHAKE output in the usual way.
/// This is called in uncommon situations.
pub