侧边栏恢复先知刊头,去掉ADMIN

- 顶部通栏不再显示先知,改为纯功能栏(面包屑/日期/状态/登出)
- 侧边栏顶部显示「先知」毛笔字
- 移除 ADMIN 标识

Co-Authored-By: new-provider/LongCat-2.0 <<EMAIL>>
)

frontend/src/admin/AdminLayout.tsx

@@ -161,9 +161,6 @@ export default function AdminLayout() {
               <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M4 6h16M4 12h16M4 18h16" />
             </svg>
           </button>
-          <h1 className="font-brush text-xl text-ink-900">
-            先知
-          </h1>
           {/* 面包屑 */}
           <nav className="hidden items-center gap-1.5 text-2xs text-ink-400 sm:flex" aria-label="面包屑">
             <a href="/admin" className="hover:text-ink-700">仪表盘</a>
@@ -219,8 +216,8 @@ export default function AdminLayout() {
         aria-label="主导航"
       >
         {/* 侧栏顶部 */}
-        <div className="flex items-center justify-between border-b border-ink-900 px-5 py-4">
-          <span className="text-2xs tracking-[0.25em] text-ink-400">ADMIN</span>
+        <div className="flex items-center border-b border-ink-900 px-5 py-4">
+          <h1 className="font-brush text-xl text-ink-900">先知</h1>
         </div>
 
         {/* 导航:分组 + 小节标题 */}