fix: fix test race condition

ref: N25B-301

src/control_backend/core/agent_system.py

@@ -1,6 +1,7 @@
 import asyncio
 import logging
 from abc import ABC, abstractmethod
+from asyncio import Task
 from collections.abc import Coroutine
 
 import zmq
@@ -75,8 +76,8 @@ class BaseAgent(ABC):
         await self.setup()
 
         # Start processing inbox and ZMQ messages
-        await self.add_behavior(self._process_inbox())
-        await self.add_behavior(self._receive_internal_zmq_loop())
+        self.add_behavior(self._process_inbox())
+        self.add_behavior(self._receive_internal_zmq_loop())
 
     async def stop(self):
         """Stops the agent."""
@@ -128,7 +129,7 @@ class BaseAgent(ABC):
         """Override this to handle incoming messages."""
         raise NotImplementedError
 
-    async def add_behavior(self, coro: Coroutine):
+    def add_behavior(self, coro: Coroutine) -> Task:
         """
         Helper to add a behavior to the agent. To add asynchronous behavior to an agent, define
         an `async` function and add it to the task list by calling :func:`add_behavior`
@@ -138,3 +139,4 @@ class BaseAgent(ABC):
         task = asyncio.create_task(coro)
         self._tasks.add(task)
         task.add_done_callback(self._tasks.discard)
+        return task