chore: apply suggestion

Changed `add_background_task` to `add_behavior` and added extra docs.

src/control_backend/agents/communication/ri_communication_agent.py

@@ -37,7 +37,7 @@ class RICommunicationAgent(BaseAgent):
 
         if await self._negotiate_connection():
             self.connected = True
-            await self.add_background_task(self._listen_loop())
+            await self.add_behavior(self._listen_loop())
         else:
             self.logger.warning("Failed to negotiate connection during setup.")