pub fn detect_available_backend() -> Result<LlmBackendKindFactory, AppError>Expand description
Resolves the available LLM CLI by probing PATH for codex first,
then claude. Returns None if neither is found.
In test environments where mock-llm is on PATH but neither
codex nor claude is, this returns Codex to preserve the
v1.0.76+ “LLM-only one-shot” contract — the mock LLM plays the
role of whichever real LLM the test expects.