chore(v1.22.1): tidy labs subtitle scale and drop dead sleep keys

Standardise the labs marker subtitle to text-xs across both the compact list
and the card grid, and build the localized name->slug lookup map once per
locale instead of re-scanning the catalog seeds per group on every render.

Add relative to the mobile section strips in the settings and admin shells so
the active chip's offsetLeft is measured from the strip, giving an exact
horizontal scroll target.

Drop the orphaned insights.sleep.headlineCaption and headlineCaptionSuffix
keys from all six locales; nothing references them after the sleep headline
removal.

src/components/admin/admin-shell.tsx

@@ -251,7 +251,7 @@ export function AdminShell({ active, children }: AdminShellProps) {
       <nav
         ref={mobileStripRef}
         aria-label={t("admin.shell.sectionsNav")}
-        className="no-scrollbar -mx-4 mb-4 snap-x snap-mandatory overflow-x-auto px-4 md:hidden"
+        className="no-scrollbar relative -mx-4 mb-4 snap-x snap-mandatory overflow-x-auto px-4 md:hidden"
       >
         <ul className="flex min-w-max gap-2">
           <li className="snap-start">