Add updateConversation support in base44 agent SDK

This is a known limitation with AI agent conversation management. The issue is that while the UI allows you to rename AI chat sessions, the changes aren't being persisted because thebase44.agents.updateConversationmethod isn't fully supported in the current SDK version.

According to the AI Agents documentation, you can manage AI agents and view conversation history by going to Dashboard → Agents tab → Conversation tab to see past conversations. However, as you've discovered, the ability to rename conversations and have those changes persist is currently limited by the SDK.

This requires an SDK update to properly support theupdateConversationmethod for agent conversation metadata like renaming and pinning.