开放多项目大屏免登录访问

需求描述：/admin/display 需要无需管理员登录即可直接查看多项目公开运行状态。

实现思路：新增公开字段白名单接口与独立大屏页面，移除该路由的管理员会话依赖，同时保留 /api/admin/overview 的鉴权并补充隐私、路由和页面回归测试。

验证：Go 全量测试通过；前端 18 个测试文件共 59 项通过，TypeScript 检查通过。

web/src/pages/AdminPage.tsx

@@ -357,7 +357,7 @@ function ProjectMaintenance({ project, onRefresh }: { project?: AdminProjectDto;
   </div>;
 }
 
-function DisplayCenter({ projects }: { projects: AdminProjectDto[] }) {
+export function DisplayCenter({ projects }: { projects: AdminProjectDto[] }) {
   const [fullscreenError, setFullscreenError] = useState(false);
   const enterFullscreen = async (projectId: string) => {
     const tile = document.querySelector(`[data-project-screen="${projectId}"]`);

web/src/pages/PublicDisplayCenterPage.test.tsx

@@ -0,0 +1,49 @@
+import { render, screen } from "@testing-library/react";
+import { describe, expect, it, vi } from "vitest";
+
+const { displayOverview } = vi.hoisted(() => ({ displayOverview: vi.fn() }));
+
+vi.mock("../api", () => ({ api: { displayOverview } }));
+vi.mock("../hooks/usePollingResource", () => ({
+  usePollingResource: (loader: (signal: AbortSignal) => unknown) => {
+    loader(new AbortController().signal);
+    return {
+      data: {
+        projects: [{
+          id: "project-1",
+          name: "东门观光车",
+          status: "RUNNING",
+          waiting_count: 1,
+          waiting_ticket_count: 1,
+          waiting_people_count: 3,
+          issued_ticket_count: 15,
+          latest_ticket_number: "00015",
+          experienced_people: 12,
+          current_batch: null,
+          estimated_wait: { available: true, lower_minutes: 5, upper_minutes: 15 },
+        }],
+        server_time: "2026-07-31T08:00:00Z",
+      },
+      loading: false,
+      refreshing: false,
+      error: null,
+      offline: false,
+      lastClientSuccessAt: new Date().toISOString(),
+      refresh: vi.fn(),
+    };
+  },
+}));
+
+import { PublicDisplayCenterPage } from "./PublicDisplayCenterPage";
+
+describe("PublicDisplayCenterPage", () => {
+  it("uses public data and renders without administrator controls", () => {
+    render(<PublicDisplayCenterPage />);
+
+    expect(displayOverview).toHaveBeenCalledOnce();
+    expect(screen.getByRole("region", { name: "项目实时监控墙" })).toBeVisible();
+    expect(screen.getByRole("heading", { name: "东门观光车" })).toBeVisible();
+    expect(screen.queryByRole("button", { name: "退出" })).not.toBeInTheDocument();
+    expect(screen.queryByRole("navigation", { name: "管理任务" })).not.toBeInTheDocument();
+  });
+});

web/src/pages/PublicDisplayCenterPage.tsx

@@ -0,0 +1,40 @@
+import { api } from "../api";
+import { FeedbackBanner, FreshnessBanner, LoadingState } from "../components/Feedback";
+import { usePollingResource } from "../hooks/usePollingResource";
+import { isTimestampStale } from "../lib/format";
+import { DisplayCenter } from "./AdminPage";
+
+export function PublicDisplayCenterPage() {
+  const resource = usePollingResource((signal) => api.displayOverview(signal), { intervalMs: 5_000 });
+  const data = resource.data;
+  const stale = Boolean(data) && isTimestampStale(resource.lastClientSuccessAt, 30_000);
+
+  return (
+    <div className="app-shell app-shell--admin app-shell--no-primary-action">
+      <a className="skip-link" href="#main-content">跳到主要内容</a>
+      <header className="app-header">
+        <div className="brand-lockup" aria-label="景区排队叫号系统">
+          <span className="brand-logo-frame" aria-hidden="true"><img className="brand-logo" src="/xiaoqikong-logo.jpg" alt="" /></span>
+          <span className="brand-lockup__text"><strong>景区排队叫号系统</strong></span>
+        </div>
+        <div className="account-menu"><span><strong>大屏中心</strong></span></div>
+      </header>
+      <main id="main-content" className="app-main">
+        <section className="admin-content" aria-label="公开大屏内容">
+          {resource.loading && !data ? <LoadingState label="正在汇总项目状态" /> : null}
+          {resource.error && !data ? (
+            <FeedbackBanner tone="danger" title="大屏数据暂时不可用" action={<button className="button button--secondary button--small" onClick={resource.refresh}>重试</button>}>
+              {resource.error.message}
+            </FeedbackBanner>
+          ) : null}
+          {data ? (
+            <>
+              <FreshnessBanner offline={resource.offline} stale={stale} timestamp={resource.lastClientSuccessAt} refreshing={resource.refreshing} errorMessage={resource.error?.message} onRetry={resource.refresh} />
+              <DisplayCenter projects={data.projects} />
+            </>
+          ) : null}
+        </section>
+      </main>
+    </div>
+  );
+}