from just router to assistant

[praneetdhoolia]

• router_graph is now just a sub-graph in the new assistant_graph

• router sub-graph routes to an mcp server

• new mcp orchestrator node uses new wrapper GetTools(MCPSessionFunction) to get mcp server tools. dynamically binds them to a language model. decides which tool to use to serve the conversation

• new mcp tool node uses new RunTool(MCPSessionFunction) to run tool on mcp server. and add tool output in a tool message.

• assistant graph decides how to handle user message conditionally

  • directly go to mcp server orchestration (if there is an active mcp server in the state)
  • otherwise use the router-subgraph to route to one

• route node decides how to proceed

  • go to mcp orchestrator node (if an mcp server has been selected to route to)
  • if no mcp server was found relevant - go to end

• mcp orchestrator node decides what to do next

  • go to router-subgraph if an i don't know (IDK) response is generated (i.e., no tool in current mcp server seems a valid candidate to handle the current conversation context
  • go to mcp_tool if a tool_call is suggested by the language model
  • go to end if a normal ai response is generated

• new prompt + configurations added for mcp orchestrator node