fix: guard against empty choices and message=None in LLM response

[qizwiz]

Problem

In tools/llm/llm.py, the LLM response is accessed without checking if choices is empty or message is None:

return completion.choices[0].message.content

This raises IndexError (empty choices) or AttributeError (message=None on filtered responses).

Fix

if not completion.choices or completion.choices[0].message is None:
    raise ValueError("LLM returned empty or filtered response")
return completion.choices[0].message.content

2 lines added, 0 deleted.

Detected by pact static analysis.