~x-ai/grok-latest → A (12:1)

A fixes a real indexing inconsistency: rank-history thread_post_index becomes proper 0-based (matching /t/tag/N), drops the silent unwrap_or(0)/1-based map, aligns types/docs/UI, and adds assertions. B only strips a decorative " · " from an embed views span—pure presentation nit with negligible lasting design value.