Build the canonical filename for an article in a given language. English
uses the bare stem (2026-01-15-breaking-en.html); other languages share
the same pattern so every language is a first-class variant. Matches the
existing news/<date>-<slug>-<lang>.html convention.
Build the canonical filename for an article in a given language. English uses the bare stem (
2026-01-15-breaking-en.html); other languages share the same pattern so every language is a first-class variant. Matches the existingnews/<date>-<slug>-<lang>.htmlconvention.