renderUnifiedLayoutHeader()/renderUnifiedLayoutFooter() (layouts/admin.php,
footer.php) dated from the pre-2.0.0 "Stage 6" migration (afa55322,
2026-02-24) and still carried its now-stale "temporary compat wrapper"
docblock plus a dead $rootPath variable in both files and a dead
'rThemes' entry (replaced by the Theme enum) in both global pull-lists.
Move the actual rendering logic into XcVm\Core\Util\LayoutRenderer;
the two global functions become one-line delegates so the ~150 existing
call sites are untouched.