fix: missing parentheses on get_status_message call in /latest endpoint

Bug

In api.py line 189, the status field in the response dict uses:

"status": interaction.current_agent.get_status_message if interaction.current_agent else "No status available",

get_status_message is a method (not a property), so without the call parentheses () the value will be a bound method object rather than a string. When FastAPI serialises the response to JSON, this either raises a TypeError or returns something like "<bound method Agent.get_status_message of ...>" instead of the actual status string.

Fix

"status": interaction.current_agent.get_status_message() if interaction.current_agent else "No status available",