Add ROBERTA classifier ranking PoC, with 77pc off the bat

agent/nodes/robertaMetrics.ts

@@ -0,0 +1,14 @@
+import { GraphNode } from "@langchain/langgraph";
+import { MessagesState } from "../state";
+import { AIMessage } from "@langchain/core/messages";
+import { evaluateWithRoberta } from "../tools/robertaCall";
+
+export const robertaMetrics: GraphNode<typeof MessagesState> = async (state) => {
+  const answer = state.proposedTriggerEvent[state.proposedTriggerEventIndex].Event
+  
+  const result = await evaluateWithRoberta({answer})
+  
+  return {
+    messages: [ new AIMessage("ROBERTA:" + result)]
+  };
+};