feat: show auto-generated conversation title for AI chat. (#17922)

## Summary
Replaces the static "Ask AI" header in the command menu with the
conversation’s auto-generated title once it’s set after the first
message.

## Changes
- **Backend:** Title is generated after the first user message (existing
behavior).
- **Frontend:** After the first stream completes, we fetch the thread
title and sync it to:
- `currentAIChatThreadTitleState` (persists across command menu
close/reopen)
- Command menu page info and navigation stack (so the title survives
back navigation)
- **Entry points:** Opening Ask AI from the left nav or command center
uses the same title resolution (explicit `pageTitle` → current thread
title → "Ask AI" fallback).
- **Race fix:** Title sync only runs when the thread that finished
streaming is still the active thread, so switching threads mid-stream
doesn’t overwrite the current thread’s title.

---------

Co-authored-by: Félix Malfait <felix@twenty.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

packages/twenty-server/src/engine/metadata-modules/ai/ai-agent-execution/utils/mapUIMessagePartsToDBParts.ts

@@ -66,6 +66,9 @@ export const mapUIMessagePartsToDBParts = (
           // Code execution parts are streamed during execution but don't need
           // to be persisted - the final result is captured in the tool part
           return null;
+        case 'data-thread-title':
+          // Thread title is a transient notification for the client
+          return null;
         default:
           {
             if (isToolPart(part)) {

packages/twenty-server/src/engine/metadata-modules/ai/ai-chat/services/agent-chat-streaming.service.ts

@@ -82,6 +82,14 @@ export class AgentChatStreamingService {
     // surfaces when awaited in onFinish.
     userMessagePromise.catch(() => {});
 
+    // Title generation runs in parallel with AI streaming so it's
+    // typically ready by the time onFinish fires
+    const titlePromise = thread.title
+      ? Promise.resolve(null)
+      : this.agentChatService
+          .generateTitleIfNeeded(thread.id, lastUserText)
+          .catch(() => null);
+
     try {
       const uiStream = createUIMessageStream<ExtendedUIMessage>({
         execute: async ({ writer }) => {
@@ -214,6 +222,16 @@ export class AgentChatStreamingService {
                   contextWindowTokens: modelConfig.contextWindowTokens,
                   conversationSize: lastStepConversationSize,
                 });
+
+                const generatedTitle = await titlePromise;
+
+                if (generatedTitle) {
+                  writer.write({
+                    type: 'data-thread-title' as const,
+                    id: `thread-title-${thread.id}`,
+                    data: { title: generatedTitle },
+                  });
+                }
               },
               sendReasoning: true,
             }),

packages/twenty-server/src/engine/metadata-modules/ai/ai-chat/services/agent-chat.service.ts

@@ -113,16 +113,6 @@ export class AgentChatService {
       await this.messagePartRepository.save(dbParts);
     }
 
-    if (uiMessage.role === AgentMessageRole.USER) {
-      const messageContent = uiMessage.parts.find(
-        (part) => part.type === 'text',
-      )?.text;
-
-      if (messageContent) {
-        this.generateTitleIfNeeded(threadId, messageContent);
-      }
-    }
-
     return savedMessage;
   }
 
@@ -148,22 +138,24 @@ export class AgentChatService {
     });
   }
 
-  private async generateTitleIfNeeded(
+  async generateTitleIfNeeded(
     threadId: string,
     messageContent: string,
-  ) {
+  ): Promise<string | null> {
     const thread = await this.threadRepository.findOne({
       where: { id: threadId },
       select: ['id', 'title'],
     });
 
     if (!thread || thread.title || !messageContent) {
-      return;
+      return null;
     }
 
     const title =
       await this.titleGenerationService.generateThreadTitle(messageContent);
 
     await this.threadRepository.update(threadId, { title });
+
+    return title;
   }
 }