fix: use plain UUID for thread-naming runs (CopilotKit#3664)

The thread naming creates an additional run, using a thread name that
was something like
"thread-naming:${originalthreadiduuid}:${newrandomuuid}" which
shockingly is not a valid uuid. This just drops the first 2 parts and
keeps the random uuid so langgraph can stop being mad.

Author: BenTaylorDev

packages/runtime/src/v2/runtime/handlers/intelligence/thread-names.ts

@@ -130,7 +130,7 @@ async function runTitleGenerationAttempt(params: {
 
   agent.setMessages(messages);
   agent.setState({});
-  agent.threadId = `thread-name:${threadId}:${randomUUID()}`;
+  agent.threadId = randomUUID();
   const { newMessages } = await agent.runAgent({
     messages,
     state: {},