frontend: add bookmark management and homepage navigation

Admin-only /bookmarks page for managing entries; homepage now renders
public bookmarks as a category-grouped navigation grid (empty state
links admin to the manager). Dashboard gains a recent-bookmarks card,
dock and main layout get a bookmark entry for admins, and the
middleware protects /bookmarks.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/app/page.tsx

@@ -5,11 +5,35 @@ import { HomePageClient } from "./home-page-client";
 const SERVER_API_URL = process.env.SERVER_API_URL || "http://backend:8080";
 const hasKeycloak = !!process.env.AUTH_KEYCLOAK_ISSUER;
 
+interface Bookmark {
+  id: number;
+  title: string;
+  url: string;
+  description: string;
+  icon: string;
+  category: string;
+}
+
+async function fetchPublicBookmarks(): Promise<Bookmark[]> {
+  try {
+    const res = await fetch(`${SERVER_API_URL}/api/bookmarks/public`, {
+      next: { revalidate: 0 },
+    });
+    if (!res.ok) return [];
+    const data = await res.json();
+    return data.bookmarks || [];
+  } catch {
+    return [];
+  }
+}
+
 export default async function HomePage() {
   const session = await auth();
   const isAuthenticated = !!session?.user;
+  const isAdmin = (session?.user as any)?.role === "admin";
 
   let healthText = "无法连接到后端服务";
+  let bookmarks: Bookmark[] = [];
 
   try {
     const res = await fetch(`${SERVER_API_URL}/api/health`, {
@@ -20,16 +44,20 @@ export default async function HomePage() {
     } else {
       healthText = `后端异常: ${res.status}`;
     }
-  } catch (err) {
+  } catch {
     healthText = "后端连接失败";
   }
 
+  bookmarks = await fetchPublicBookmarks();
+
   return (
     <Suspense>
       <HomePageClient
         isAuthenticated={isAuthenticated}
+        isAdmin={isAdmin}
         healthText={healthText}
         hasKeycloak={hasKeycloak}
+        bookmarks={bookmarks}
       />
     </Suspense>
   );