fix: replace print() with proper logging (#29, #51)

src/infrastructure/events/bus.py

@@ -63,7 +63,7 @@ class EventBus:
 
         @bus.subscribe("agent.task.*")
         async def handle_task(event: Event):
-            print(f"Task event: {event.data}")
+            logger.debug(f"Task event: {event.data}")
 
         await bus.publish(Event(
             type="agent.task.assigned",