Freshness Ribbon

Per-section last-content-review date badge on each section heading (right end, after [edit] pencil). Three-stop colour scale: fresh (green, ≤90 days) / stale (amber, 91–365 days) / archived (gray, >365 days). Data source: git-blame at section level (excluding whitespace-only commits) or frontmatter content_reviewed_on override. dateModified per-section WebPageElement JSON-LD emission.