- Add LITELLM = "litellm" to LLMProviderType enum (already in HEAD from prev commit)
- Add comment in LLMClient.__init__ explaining standard Bearer auth for LiteLLM
- Add regression test test_provider_type_enum_values — guard against value drift
- Add test_litellm_client_uses_default_bearer_auth — verify no extra headers
- Clean up duplicate @RELATION lines in models.py
- All 20 backend + 4 frontend tests pass