[Tunix] Update BaseAgent to accept observations with a "prompts" key rather than "question".

PiperOrigin-RevId: 875785435

Author: lc5211

tunix/rl/agentic/agents/base_agent.py

@@ -168,9 +168,9 @@ def _observation_to_messages(
       info: Additional information from the environment.
     """
     del reward, done, info  # Unused in default implementation.
-    if isinstance(observation, dict) and "question" in observation:
+    if isinstance(observation, dict) and "prompts" in observation:
       self._messages.append(
-          {"role": "user", "content": observation["question"]}
+          {"role": "user", "content": observation["prompts"]}
       )
     elif isinstance(observation, str):
       self._messages.append({"role": "user", "content": observation})