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/online/page.tsx

@@ -29,12 +29,9 @@ export default async function OnlineUsersPage({
 
 	return (
 		<div className="space-y-6">
-			<div>
-				<h1 className="text-3xl font-bold tracking-tight">Online Users</h1>
-				<p className="text-muted-foreground">
-					Currently online users ({result.total} connected)
-				</p>
-			</div>
+			<p className="text-muted-foreground">
+				Currently online users ({result.total} connected)
+			</p>
 
 			<OnlineTable
 				data={{