fix: chat loses conversation context between messages

Remove revalidatePath('/chat') from createConversation — it caused
the server to re-render the /chat page after each new conversation,
which reset the useChat hook state and created a new conversation
for every message instead of continuing the existing one.

Sidebar now refreshes client-side after streaming completes.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

memento-note/components/chat/chat-container.tsx

@@ -60,12 +60,14 @@ export function ChatContainer({ initialConversations, notebooks, webSearchAvaila
   }, [isLoading, t])
 
   // Sync historyMessages after each completed streaming response
-  // so the display doesn't revert to stale history
+  // so the display doesn't revert to stale history.
+  // Also refresh sidebar so new conversation appears.
   useEffect(() => {
     if (status === 'ready' && messages.length > 0) {
       setHistoryMessages([...messages])
+      refreshConversations()
     }
-  }, [status, messages])
+  }, [status, messages, refreshConversations])
 
   // Load conversation details when the user selects a different conversation
   useEffect(() => {