chore(deps): bump yaad submodule to cocoindex-adoption build (#16)

Points the vendored yaad submodule at the new yaad commit carrying
model-aware embedding caching, asymmetric retrieval, the model-scoped
persisted vector store, and the pure-Go brace chunker. Keeps hawk's
embedded yaad in sync with canonical yaad.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: Patel230