"""Aurelius core — source-agnostic graph-intelligence engine.

Layers (top to bottom):
  navigator.py       GraphNavigator: bidirectional semantic best-first search
  discovery.py       relate() strength scoring + discover() hidden-link engine
  representation.py  node2vec structural embeddings + text/struct fusion
  embedding.py       text-embedding model singleton + per-search caches
  store.py           persistent graph + vector store (SQLite; pgvector-ready)
  source.py          the GraphSource protocol every adapter implements
  types.py           NodeRef / Edge — the only vocabulary the core speaks

Nothing in this package may import from adapters/ — adapters depend on
core, never the reverse. That direction is what keeps the engine reusable
across Wikipedia, papers, code, biology, news, and finance.
"""