Resolve externalized specifier with internal resolver

Editor assessment

`fix(config)` types and scopes this precisely, and the subject correctly uses the codebase's own vocabulary ('externalized specifier', 'internal resolver'), which makes it searchable for maintainers. For outsiders, though, the phrase is dense and unexplained; one or two body sentences — what specifier was being mishandled and the observable symptom, such as a failed load or duplicated module instance — would make the changelog entry meaningful beyond the core team. Structure is otherwise solid: lowercase start, imperative verb, no trailing period, and a length well within safe bounds.