Store ownership

Three facts make it matter who closes a store:

• aclose() on a SQLite store isn't final: a later call reopens the connection.
• async with pipeline closes every entry in closeables each time the block exits.
• A store's lock belongs to the first event loop that contends for it. Using the same instance from a second loop fails, but only when both use it at once, so a quiet test passes and a busy UI breaks.

So give every store instance exactly one owner, the scope that outlives all its users, and let only the owner call aclose(). Use each instance from one event loop. Everything else borrows: AsyncHybridSearcher, the edge sources, and AsyncCompositeIngestor never close a store.

Deployment	Owner of the SQLite stores	Pipeline closeables
Pipeline and UI in separate processes	each process, for the instances it opened on the shared files	lists the pipeline's own instances
One-shot script that ingests and queries inside async with pipeline	the pipeline	lists the stores; queries run inside the block
Long-lived application on one event loop that starts ingest runs	the application, which closes them on shutdown	must not list them, or the end of each run closes them and the next query reopens an unowned connection
Blocking ETLPipeline plus an application on its own loop	two sets of instances on the same files: one used by the pipeline's background loop, one by the application's loop	lists the pipeline's set

SQLite's WAL mode lets one process read while another writes.