The OptimalService singleton published the instance before initialize()
finished, so a concurrent caller could observe _initialized=False and hit
"OptimalService not initialized" during RAG indexing. Build the instance,
initialize it, then publish under a lazily-bound asyncio lock so all callers
share a fully-initialized singleton.
roboco_kb_search forwarded the legacy alias index_types=['docs'], which is
not a valid IndexType value (the enum value is 'documentation'), producing a
400 at the route. Normalize the alias in the client before the request is
sent and fix the misleading tool docstring.
The mentor route let exceptions from mentor.ask escape as a bare 500 that
masked the real cause. Catch, log the true upstream error with stack, and
surface it in the response detail so failures are diagnosable.
