Add authentication features for admin access

- Introduce a new `auth` module with login, logout, and user verification endpoints for a single admin user.
- Update backend routes to require admin authentication for sensitive operations, enhancing security.
- Modify frontend components to include an authentication provider and gate, ensuring only authorized users can access the application.
- Implement a login page for admin access, improving user experience and security management.
- Update API request handling to redirect unauthorized users to the login page, ensuring proper access control.

frontend/src/components/layout/Sidebar.tsx

@@ -1,7 +1,7 @@
 "use client";
 
 import Link from "next/link";
-import { usePathname } from "next/navigation";
+import { usePathname, useRouter } from "next/navigation";
 import {
   Bot,
   Boxes,
@@ -11,9 +11,11 @@ import {
   Database,
   Wrench,
   Home,
+  LogOut,
   PlayCircle,
   Video,
 } from "lucide-react";
+import { useAuth } from "@/components/auth/AuthProvider";
 
 type SidebarProps = {
   collapsed: boolean;
@@ -39,6 +41,8 @@ const monitorSubItems: NavItem[] = [
 
 export function Sidebar({ collapsed, onToggle }: SidebarProps) {
   const pathname = usePathname();
+  const router = useRouter();
+  const { user, logout } = useAuth();
 
   // 精确匹配或前缀匹配(带 / 边界),让 /assistants/xxx 也高亮"创建助手"
   const isActive = (href: string) =>
@@ -47,6 +51,11 @@ export function Sidebar({ collapsed, onToggle }: SidebarProps) {
   const componentActive = componentSubItems.some((item) => isActive(item.href));
   const monitorActive = monitorSubItems.some((item) => isActive(item.href));
 
+  async function handleLogout() {
+    await logout();
+    router.replace("/login");
+  }
+
   return (
     <aside
       className={[
@@ -193,10 +202,9 @@ export function Sidebar({ collapsed, onToggle }: SidebarProps) {
       </nav>
 
       <div className="shrink-0 space-y-2 border-t border-sidebar-border bg-sidebar p-3 shadow-[0_-12px_24px_rgba(0,0,0,0.12)]">
-        {/* 个人中心 */}
         <Link
           href="/profile"
-          title={collapsed ? "个人中心 · 管理员" : undefined}
+          title={collapsed ? `个人中心 · ${user?.displayName ?? "超级管理员"}` : undefined}
           className={[
             "group relative flex w-full items-center overflow-hidden rounded-2xl border py-2 text-left transition-[background-color,color,border-color,box-shadow,transform] duration-200 active:scale-[0.98]",
             isActive("/profile")
@@ -229,11 +237,30 @@ export function Sidebar({ collapsed, onToggle }: SidebarProps) {
             ].join(" ")}
           >
             <span className="block truncate text-sm font-medium text-foreground">
-              管理员
+              {user?.displayName ?? "超级管理员"}
             </span>
           </span>
         </Link>
 
+        <button
+          onClick={handleLogout}
+          title={collapsed ? "退出登录" : undefined}
+          className={[
+            "group flex h-10 w-full items-center overflow-hidden rounded-full border border-hairline-strong text-sm text-muted-foreground transition-[background-color,color,border-color,transform] duration-200 hover:bg-surface-strong hover:text-foreground active:scale-[0.98]",
+            collapsed ? "justify-center gap-0 px-0" : "justify-between gap-2 px-3.5",
+          ].join(" ")}
+        >
+          <span
+            className={[
+              "min-w-0 truncate transition-all duration-300 ease-[cubic-bezier(0.22,1,0.36,1)]",
+              collapsed ? "w-0 opacity-0 -translate-x-2" : "opacity-100 translate-x-0",
+            ].join(" ")}
+          >
+            退出登录
+          </span>
+          <LogOut size={18} className="shrink-0 transition-transform duration-200 group-hover:translate-x-0.5" />
+        </button>
+
         {/* 收起 / 展开侧栏 */}
         <button
           onClick={onToggle}