Show tool call details instead of empty messages in chat

[iNicholasBE]

Problem

When the AI agent makes tool calls during a conversation, empty message bubbles appear in the chat UI. This creates a confusing experience for the user.

Expected behavior

Since tool calls result in two messages (the tool call and the tool response), we should show what's happening rather than hiding them:

• Display which tool is being called and what it's doing
• Show the tool response/result

This gives the user visibility into the agent's actions and makes the conversation flow more transparent.

Current behavior

Empty/blank message bubbles appear in the chat when tool calls occur.

----- Later in the chat another draft reply ----

[auloin]

I've a submitted a #34, should solve the empty bubbles issue but doesn't handle displaying the tool call details.

This one might be a bit more complex and might require a different architecture (e.g., using a streaming response or a different endpoint for tool calls), to be able to see the tool calls in the live chat.