feat(client): add long-lived multi-server client that reuses sessions…#419

kulikrch wants to merge 2 commits intolangchain-ai:mainlangchain-ai/langchain-mcp-adapters:mainfrom

kulikrch:fix-362-189-long-lived-session-load-mcp-toolskulikrch/langchain-mcp-adapters:fix-362-189-long-lived-session-load-mcp-toolsCopy head branch name to clipboard