_llm_health.py imported langchain_core, langchain_openai, and openai at
module level. These packages are only installed in the agent container
(requirements-agent.txt), not the backend container (requirements-backend.txt).
Moved all langchain/openai imports inside _check_llm_provider_health() with
ImportError handled gracefully — returns 'unavailable' status instead of
ModuleNotFoundError 500 error.
Root cause: the /api/agent/llm-status endpoint runs in the backend container,
which has httpx but not langchain. The agent container has all LLM deps.
Verified: import without langchain succeeds, health check returns 'unavailable'.
busya
beed41d6c9