Citation audit: crypto modules (ntt, pqc)

[erfanjazebnikoo]

Publication-grade references for the crypto modules: specific algorithm/
theorem/section numbers, not just top-level paper links. Covers ntt now
(docs/algorithms/ntt.md and the inline docstring citations added in #86/#87)
and each pqc submodule as it lands (gated by #62/#65/#66).

Sepand offered to contribute references for this directly.

Scope:

• Verify every citation in docs/algorithms/ntt.md points to the correct
  edition/page/section, not just the paper title
• Verify every public NTT function's docstring citation (added in fix(ntt): cross-validate against PQClean reference, add citation provenance #86)
  matches the docs page
• Same treatment for pqc modules as their docs pages are written