Summary

The 2026-09-30 estate composition audit found every page ships a per-anchor data-sidebar-search="..." attribute on all ~730 sidebar anchors while the entire JS bundle reads it in exactly ONE place — the cosmetic cleanGeneratedTopicLabels loop, which skips absent attributes. Sidebar search is served by the lazy assets/js/search-index.js asset plus the title/textContent fallback harvester (collectSiteSearchFallbackPages reads title + textContent + data-card-search, never data-sidebar-search). The attribute is dead payload (~30 KB decoded on EVERY page of the site).

• _includes/sidebar.html: stops emitting the attribute (2 emission site(s) removed; title tooltips and aria-label a11y enrichment untouched).
• assets JS: the cleanup list drops the dead attribute name (title/aria-label cleanup unchanged).
• _config.yml: ui_bundle_version bumped for cache-busting.

Zero editorial content touched; search behaviour unchanged (index asset path); zero deploy actions in the producing session.

Part of the estate page-weight trim work item (alpha-production:estate-sidebar-search-index-bundle:v1, #4439).