LangGraph v0.2: Increased customization with new checkpointer libraries

LangGraph v0.2 introduces a new ecosystem of checkpointer libraries that simplify the creation and customization of checkpointers, allowing users to build more resilient Language Model (LLM) applications with features such as session memory, robust error recovery, and human-in-the-loop capabilities. The release includes dedicated checkpoint libraries for SQLite, Postgres, and an in-memory checkpointer implementation for experimentation. LangGraph v0.2 also provides a blueprint for community members to implement their own optimized, production-ready checkpointers for their favorite database. Additionally, the new runtime, LangGraph Cloud, offers infrastructure for deploying agents at scale with fault-tolerant scalability and robust Postgres checkpointer out-of-the-box.