Add debug mode to log messages and tool call output to stdout

[djfarrelly]

During local debugging, it's helpful to be able to just see messages streamed to stdout.

<network-name>:user: How do I aggregate an integer column across a date column by week? (the prompt)
<network-name>:router: Routing to <agent-name>
<agent-name>:assistant: This is a response from an agent
<agent-name>:tool_call: { "result": 10 }