[ChromaDB vector store]  <- lives in .brain/, isolated per workspace
        |
        v  Query triggers L1 -> L2 -> L3 -> L4
[L1: Vector search]       L2 distance, top-N results
[L2: Lexical re-rank]     boosts exact keyword + entity matches
[L3: Mode routing]        cloud / local / hybrid
[L4: Synthesis]           answer with inline #file:line citations
        |
        v
[Your IDE gets clean, cited context. Not a file dump.]