flush method
Persist what has been indexed so far, keeping the store open.
Call it after a bulk index, and from wherever the app learns it is going away. On qdrant this is what makes an index survive the process at all — without it the points sit in the shard's in-RAM segment and a background kill takes them. See VectorStoreRepository.flush for the other backends.
Implementation
Future<void> flush() => FlutterGemmaPlugin.instance.flushVectorStore();