fix(ui): remove sub-AA opacity dimming from informational text

The muted-foreground token is AA-tuned in both themes; the /70 and /80
opacity modifiers silently undid that (2.9-4.2:1 measured). Every
informational text node drops the modifier for the full token: sleep
hypnogram captions, learning-gate caveat, integration-card setup hints,
module lock notes, glucose panel and token-footer meta, invite-token
hint, wizard hint, notification channel labels and disabled notes (the
disabled state reads through the note and the disabled switches, not
through dimming), plus the resting state of the timestamp, suggestion
chip and sidebar-collapse controls. User-authored mood notes move to
foreground text-sm — user data is never muted. Decorative non-text
strokes (sparkline grid, calendar dot, titration connector) keep their
opacity; icons keep the /60 graphics floor.

src/components/admin/invite-tokens-section.tsx

@@ -325,7 +325,7 @@ export function InviteTokensSection() {
           <p className="text-muted-foreground mt-1 pl-7 text-xs">
             {t("admin.invites.description")}
           </p>
-          <p className="text-muted-foreground/80 mt-1 flex items-center gap-1.5 pl-7 text-xs">
+          <p className="text-muted-foreground mt-1 flex items-center gap-1.5 pl-7 text-xs">
             <ShieldCheck className="size-3.5 shrink-0" aria-hidden="true" />
             {t("admin.invites.adminOnlyHint")}
           </p>