improve admin release and deployment safeguards

src/App.tsx

@@ -532,8 +532,11 @@ function Sidebar({
 
   return (
     <aside className="fixed inset-y-0 left-0 hidden w-[17rem] flex-col border-r border-border bg-sidebar px-3 py-4 lg:flex">
-      <div className="mb-8 flex shrink-0 justify-center px-4 py-3">
-        <img className="h-5 w-auto object-contain" src="/assets/brand/header.webp" alt="Autonomy Studio" />
+      <div className="mb-8 shrink-0 px-4 py-3 text-center">
+        <img className="mx-auto h-5 w-auto object-contain" src="/assets/brand/header.webp" alt="Autonomy Studio" />
+        <p className="mt-2 text-[8px] font-medium uppercase tracking-[0.18em] text-muted-foreground">
+          Studio Management System
+        </p>
       </div>
 
       <nav className="scrollbar-stable min-h-0 flex-1 space-y-5 overflow-y-auto pr-2">
@@ -767,10 +770,13 @@ function LoginPage({ onLogin }: { onLogin: (admin: CurrentAdmin) => void }) {
     <div className="min-h-screen bg-background px-4 text-foreground">
       <div className="mx-auto flex min-h-screen w-full max-w-sm items-center justify-center py-12">
         <div className="w-full rounded-lg border border-border bg-card/95 shadow-2xl">
-          <div className="px-6 pb-5 pt-8">
+          <div className="px-6 pb-6 pt-8">
             <div className="flex justify-center">
               <img className="h-6 w-auto object-contain" src="/assets/brand/header.webp" alt="Autonomy Studio" />
             </div>
+            <p className="mt-2 text-center text-[9px] font-medium uppercase tracking-[0.18em] text-muted-foreground">
+              Studio Management System
+            </p>
             <div className="mt-7 text-center">
               <h1 className="text-xl font-semibold tracking-tight">관리자 로그인</h1>
               <p className="mt-2 text-sm text-muted-foreground">계정 정보를 입력해 주세요.</p>