frontend: redesign homepage with magic dock and login dialog

- Replace top login/register buttons with magic dock navigation
- Add dock items: home, downloads, blog, and conditional login/logout
- Show dashboard icon in dock when authenticated
- Extract HomePageClient for client-side dialog state

frontend/app/page.tsx

@@ -1,8 +1,14 @@
-import { BlurFade } from "@/components/magicui/blur-fade";
+import { Suspense } from "react";
+import { auth } from "@/auth";
+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;
 
 export default async function HomePage() {
+  const session = await auth();
+  const isAuthenticated = !!session?.user;
+
   let healthText = "无法连接到后端服务";
 
   try {
@@ -19,46 +25,12 @@ export default async function HomePage() {
   }
 
   return (
-    <div className="flex min-h-screen flex-col items-center justify-center bg-gradient-to-br from-slate-50 to-slate-100 p-4">
-      <BlurFade inView delay={0.1}>
-        <h1 className="mb-4 text-center text-4xl font-extrabold tracking-tight text-slate-900">
-          EvanPage
-        </h1>
-      </BlurFade>
-
-      <BlurFade inView delay={0.2}>
-        <p className="mb-8 max-w-md text-center text-lg text-slate-600">
-          全栈基础框架
-        </p>
-      </BlurFade>
-
-      <BlurFade inView delay={0.3}>
-        <div className="rounded-2xl border bg-white/80 px-8 py-6 shadow-lg backdrop-blur">
-          <p className="text-center text-sm font-medium text-slate-500">
-            后端状态
-          </p>
-          <p className="mt-2 text-center text-xl font-semibold text-slate-800">
-            {healthText}
-          </p>
-        </div>
-      </BlurFade>
-
-      <BlurFade inView delay={0.4}>
-        <div className="mt-8 flex gap-4">
-          <a
-            href="/login"
-            className="rounded-lg bg-slate-900 px-5 py-2.5 text-sm font-medium text-white hover:bg-slate-800"
-          >
-            登录
-          </a>
-          <a
-            href="/register"
-            className="rounded-lg border border-slate-300 bg-white px-5 py-2.5 text-sm font-medium text-slate-700 hover:bg-slate-50"
-          >
-            注册
-          </a>
-        </div>
-      </BlurFade>
-    </div>
+    <Suspense>
+      <HomePageClient
+        isAuthenticated={isAuthenticated}
+        healthText={healthText}
+        hasKeycloak={hasKeycloak}
+      />
+    </Suspense>
   );
 }