Fix updating specific conversation by id from the chat API endpoint

- Use the conversation id of the retrieved conversation rather than the
  potentially unset conversation id passed via API
- await creating new chat when no chat id provided and no existing
  conversations exist

src/khoj/database/adapters/__init__.py

@@ -395,7 +395,7 @@ class ConversationAdapters:
     @staticmethod
     def get_conversation_by_user(
         user: KhojUser, client_application: ClientApplication = None, conversation_id: int = None
-    ):
+    ) -> Optional[Conversation]:
         if conversation_id:
             conversation = (
                 Conversation.objects.filter(user=user, client=client_application, id=conversation_id)
@@ -437,7 +437,7 @@ class ConversationAdapters:
     @staticmethod
     async def aget_conversation_by_user(
         user: KhojUser, client_application: ClientApplication = None, conversation_id: int = None, title: str = None
-    ):
+    ) -> Optional[Conversation]:
         if conversation_id:
             return await Conversation.objects.filter(user=user, client=client_application, id=conversation_id).afirst()
         elif title:
@@ -445,7 +445,7 @@ class ConversationAdapters:
         else:
             return await (
                 Conversation.objects.filter(user=user, client=client_application).order_by("-updated_at").afirst()
-            ) or Conversation.objects.acreate(user=user, client=client_application)
+            ) or await Conversation.objects.acreate(user=user, client=client_application)
 
     @staticmethod
     async def adelete_conversation_by_user(

src/khoj/routers/api_chat.py

@@ -330,7 +330,7 @@ async def chat(
             intent_type=intent_type,
             inferred_queries=[improved_image_prompt],
             client_application=request.user.client_app,
-            conversation_id=conversation_id,
+            conversation_id=conversation.id,
             compiled_references=compiled_references,
             online_results=online_results,
         )
@@ -347,7 +347,7 @@ async def chat(
         conversation_commands,
         user,
         request.user.client_app,
-        conversation_id,
+        conversation.id,
         location,
         user_name,
     )