// Select a declared module without guessing a provider from the model id.
// Legacy entries may map through exactly one enabled module; ambiguity fails closed.
export function selectModelProvider(modules, selection) {
  const candidates = modules.filter(({name, module}) => {
    if (selection?.module && selection.module !== name) return false;
    try {
      const route = module.route({selection, harness:null});
      return route && !route.code && route.provider === selection?.provider && route.model === selection?.model;
    } catch { return false; }
  });
  return candidates.length === 1 ? candidates[0] : null;
}