- Extract duplicated TOC predicate to _partials/toc-enabled.html
(single.html + footer.html were both computing the same 6-line gate).
- Inline _partials/head/og-image.html into head/seo.html — single caller,
the fallback chain is the contract; the partial wasn't earning its
override surface.
- Drop 6 unused i18n keys: postedOn, tags, categories, archive, noResults,
copyright. None referenced by any template (verified via grep). Also
removed an accidental duplicate of the callout title block; vi.yml
reorganized into thematic groups.
Behavior unchanged. Smoke (11 checks) + Hugo build clean. CSS bundle
unchanged at 3962 B gz.
