Clean up admin hub UX: tabs, chrome, and redundant headers.

Wire orphan routes into hub tabs, group Radio into primary/tools rows, show theme/language once on desktop, and remove duplicate page titles under AdminHubChrome.

Co-authored-by: Cursor <[email protected]>

src/app/admin/theme/page.tsx

@@ -372,20 +372,6 @@ export default async function AdminTheme({
 
 	return (
 		<main>
-			<div className="flex items-center gap-3 mb-6">
-				<div className="w-10 h-10 rounded-xl bg-gradient-to-br from-[var(--admin-accent)]/20 to-[var(--admin-accent)]/5 grid place-items-center">
-					<span className="text-lg">🎨</span>
-				</div>
-				<div>
-					<h1 className="m-0 text-xl font-extrabold text-[var(--admin-text)]">
-						{t("title")}
-					</h1>
-					<p className="m-0 text-xs text-[var(--admin-text-muted)] mt-0.5">
-						{t.rich("subtitle", { code: (chunks) => <code>{chunks}</code> })}
-					</p>
-				</div>
-			</div>
-
 			{sp.saved ? (
 				<div className="mb-4 p-3 rounded-lg theme-status-success text-xs">
 					{t("saved")}