Addresses review on #2264: the localization helper had one broad catch around
both dynamic producer resolution and injector execution, so it couldn't tell a
benign 'producer not in this environment' from a real injector/fetch failure,
and emitted no diagnostic. Split into loadFontInjector() (returns null when the
module is absent — silent fail-open) and localizeWithProducer() (warns ONCE per
distinct message when the injector itself throws, then fails open). Per-family
resolution failures remain the injector's own responsibility (producer's
warnUnresolvedFonts). The localizer seam is injectable; tests now cover success,
producer-unavailable, injector-throw, warn dedup, and call-site integration.
The CLI test job builds with --filter '!@hyperframes/producer', and render.ts
imports producer only as a type — so a static import("@hyperframes/producer")
in the font-localization helper failed Vitest's transform-time module
resolution ("Failed to resolve entry for package"), breaking checkBrowser
tests and the helper's own test. Keep the specifier out of the static module
graph (@vite-ignore + variable specifier) so it resolves at runtime only:
production/installed CLI has producer in node_modules and localizes fonts;
the test env fail-opens to the plain bundle. Localizer is now injectable so
the helper's unit tests cover it without needing producer resolvable.
Vance Ingalls