LangGraph SQLite Checkpoint

Implementation of LangGraph CheckpointSaver that uses SQLite DB (both sync and async, via aiosqlite)

Security

[!IMPORTANT] Set LANGGRAPH_STRICT_MSGPACK=true or pass an explicit allowed_msgpack_modules list when creating your checkpointer. This restricts checkpoint deserialization to known-safe types, preventing code execution if the database is compromised. See the langgraph-checkpoint README for details.