Function select_inference 

pub fn select_inference() -> impl SeverityInference

Selects the concrete SeverityInference impl at compile time, milestone-gated by the inference Cargo feature (§17, §G.14): NoInference when the feature is off, CommitInference (a real git-backed adapter, §G.6.4) when it’s on. CommitInference needs no workspace/runner context of its own – SeverityInference::infer receives the caller’s GitAccess per call – so this needs no parameters and no lifetime.