👻 fix: Prevent Async Title Generation From Recreating Deleted Conversations (#11797)

* 🐛 fix: Prevent deleted conversations from being recreated by async title generation

  When a user deletes a chat while auto-generated title is still in progress,
  `saveConvo` with `upsert: true` recreates the deleted conversation as a ghost
  entry with only a title and no messages. This adds a `noUpsert` metadata option
  to `saveConvo` and uses it in both agent and assistant title generation paths,
  so the title save is skipped if the conversation no longer exists.

* test:  conversation creation logic with noUpsert option

  Added new tests to validate the behavior of the `saveConvo` function with the `noUpsert` option. This includes scenarios where a conversation should not be created if it doesn't exist, updating an existing conversation when `noUpsert` is true, and ensuring that upsert behavior remains the default when `noUpsert` is not provided. These changes improve the flexibility and reliability of conversation management.

* test: Clean up Conversation.spec.js by removing commented-out code

  Removed unnecessary comments from the Conversation.spec.js test file to improve readability and maintainability. This includes comments related to database verification and temporary conversation handling, streamlining the test cases for better clarity.

api/models/Conversation.spec.js

@@ -106,6 +106,47 @@ describe('Conversation Operations', () => {
       expect(result.conversationId).toBe(newConversationId);
     });
 
+    it('should not create a conversation when noUpsert is true and conversation does not exist', async () => {
+      const nonExistentId = uuidv4();
+      const result = await saveConvo(
+        mockReq,
+        { conversationId: nonExistentId, title: 'Ghost Title' },
+        { noUpsert: true },
+      );
+
+      expect(result).toBeNull();
+
+      const dbConvo = await Conversation.findOne({ conversationId: nonExistentId });
+      expect(dbConvo).toBeNull();
+    });
+
+    it('should update an existing conversation when noUpsert is true', async () => {
+      await saveConvo(mockReq, mockConversationData);
+
+      const result = await saveConvo(
+        mockReq,
+        { conversationId: mockConversationData.conversationId, title: 'Updated Title' },
+        { noUpsert: true },
+      );
+
+      expect(result).not.toBeNull();
+      expect(result.title).toBe('Updated Title');
+      expect(result.conversationId).toBe(mockConversationData.conversationId);
+    });
+
+    it('should still upsert by default when noUpsert is not provided', async () => {
+      const newId = uuidv4();
+      const result = await saveConvo(mockReq, {
+        conversationId: newId,
+        title: 'New Conversation',
+        endpoint: EModelEndpoint.openAI,
+      });
+
+      expect(result).not.toBeNull();
+      expect(result.conversationId).toBe(newId);
+      expect(result.title).toBe('New Conversation');
+    });
+
     it('should handle unsetFields metadata', async () => {
       const metadata = {
         unsetFields: { someField: 1 },
@@ -122,7 +163,6 @@ describe('Conversation Operations', () => {
 
   describe('isTemporary conversation handling', () => {
     it('should save a conversation with expiredAt when isTemporary is true', async () => {
-      // Mock app config with 24 hour retention
       mockReq.config.interfaceConfig.temporaryChatRetention = 24;
 
       mockReq.body = { isTemporary: true };
@@ -135,7 +175,6 @@ describe('Conversation Operations', () => {
       expect(result.expiredAt).toBeDefined();
       expect(result.expiredAt).toBeInstanceOf(Date);
 
-      // Verify expiredAt is approximately 24 hours in the future
       const expectedExpirationTime = new Date(beforeSave.getTime() + 24 * 60 * 60 * 1000);
       const actualExpirationTime = new Date(result.expiredAt);
 
@@ -157,7 +196,6 @@ describe('Conversation Operations', () => {
     });
 
     it('should save a conversation without expiredAt when isTemporary is not provided', async () => {
-      // No isTemporary in body
       mockReq.body = {};
 
       const result = await saveConvo(mockReq, mockConversationData);
@@ -167,7 +205,6 @@ describe('Conversation Operations', () => {
     });
 
     it('should use custom retention period from config', async () => {
-      // Mock app config with 48 hour retention
       mockReq.config.interfaceConfig.temporaryChatRetention = 48;
 
       mockReq.body = { isTemporary: true };