All ten tool bodies opened their own `HaikuRAG`, so every tool call paid a
connection open and, on object storage, refetched the index the previous call had
just cached. The client is now opened once, lazily so that calling a tool
function directly still works, and eagerly from the lifespan so an unopenable
database fails startup instead of every call. Teardown clears the cached client
in a finally, since `_lifespan_manager` can be re-entered and would otherwise
hand out a closed connection, including when the close itself fails.
`delete_document` no longer opens its own connection with `skip_validation=True`.
Keeping it separate broke consistency once connections became long-lived: the
delete committed on one connection while reads served from another, which with a
30s consistency interval showed the deleted document as still present. A
connection always sees its own writes, so sharing one is what makes delete
visible to the next read.
So the server no longer opts out of embedding-config validation. Drift that
validation rejects now fails MCP startup, where before the server started and
only `delete_document` worked while every read returned empty. Same-dimension
identity drift still starts a read-only server, matching every other read verb.
Delete under drift is now a CLI operation; CLAUDE.md and the CHANGELOG record it.