fix(frontend): preserve agent context in thread history routes (#1771)

* fix(frontend): preserve agent context in thread history routes

* fix(frontend): preserve agent thread fallback context

* style(frontend): format thread route utils test

---------

Co-authored-by: luoxiao6645 <luoxiao6645@gmail.com>

frontend/src/core/threads/utils.ts

@@ -1,9 +1,28 @@
 import type { Message } from "@langchain/langgraph-sdk";
 
-import type { AgentThread } from "./types";
+import type { AgentThread, AgentThreadContext } from "./types";
 
-export function pathOfThread(threadId: string) {
-  return `/workspace/chats/${threadId}`;
+type ThreadRouteTarget =
+  | string
+  | Pick<AgentThread, "thread_id" | "context">
+  | {
+      thread_id: string;
+      context?: Pick<AgentThreadContext, "agent_name"> | null;
+    };
+
+export function pathOfThread(
+  thread: ThreadRouteTarget,
+  context?: Pick<AgentThreadContext, "agent_name"> | null,
+) {
+  const threadId = typeof thread === "string" ? thread : thread.thread_id;
+  const agentName =
+    typeof thread === "string"
+      ? context?.agent_name
+      : thread.context?.agent_name;
+
+  return agentName
+    ? `/workspace/agents/${encodeURIComponent(agentName)}/chats/${threadId}`
+    : `/workspace/chats/${threadId}`;
 }
 
 export function textOfMessage(message: Message) {