Add simple agent communication demo

[rbren]

Summary

This PR adds a simplified version of the inter-agent communication demo as simple_agent_communication.py.

Changes Made

• Custom Agent Creation: Instead of using the default agent from presets, creates a custom agent with only messaging tools
• Removed Receive Message Tool: Eliminates the "receive message" tool and implements direct message delivery instead
• Streamlined Communication: Messages are automatically delivered to agents during conversation steps rather than requiring explicit polling
• Simplified Architecture: Agents only have access to the send_message tool, making the communication flow more straightforward

Key Differences from Original Demo

1. Agent Creation: Uses Agent() constructor directly instead of get_default_agent()
2. Tool Simplification: Only includes messaging tools, no other default tools
3. Message Delivery: Implements check_and_deliver_messages() function that automatically delivers pending messages
4. Reduced Complexity: Eliminates the need for agents to actively check for messages

Testing

The demo maintains the same collaborative conversation structure where Alice and Bob discuss planning a Python project, but with a much simpler messaging architecture.

Files Added

• simple_agent_communication.py - Simplified inter-agent communication demo

@rbren can click here to continue refining the PR