feat: assemble responsive app shell navigation

tests/component/router.test.jsx

@@ -1,24 +1,72 @@
 // @vitest-environment jsdom
 
 import { render, screen } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
 import { describe, expect, it } from "vitest";
 
-import { createAnonymousSessionAdapter } from "../../src/adapters/auth/external-session-adapter.js";
+import {
+  createAnonymousSessionAdapter,
+  createDemoSessionAdapter,
+} from "../../src/adapters/auth/external-session-adapter.js";
 import { AppRouter } from "../../src/presentation/routes/app-router.jsx";
 
 describe("application router", () => {
-  it("renders not-found without making an API request", () => {
+  it("renders the app shell and not-found route without an API request", async () => {
     window.history.pushState({}, "", "/missing");
     render(<AppRouter authSession={createAnonymousSessionAdapter()} />);
+
     expect(
-      screen.getByRole("heading", { name: "페이지를 찾을 수 없습니다." }),
+      await screen.findByRole("heading", {
+        name: "페이지를 찾을 수 없습니다.",
+      }),
     ).toBeVisible();
+    expect(screen.getByRole("navigation", { name: "주요 탐색" })).toBeVisible();
+    expect(screen.getByRole("main")).toBeVisible();
   });
 
-  it("shows session-required UX without claiming authorization", () => {
+  it("navigates between registry-backed example routes", async () => {
+    const user = userEvent.setup();
+    window.history.pushState({}, "", "/");
+    render(<AppRouter authSession={createAnonymousSessionAdapter()} />);
+
+    await user.click(
+      await screen.findByRole("link", { name: "UI 구성요소", exact: true }),
+    );
+
+    expect(
+      await screen.findByRole("heading", { name: "UI 구성요소", level: 1 }),
+    ).toBeVisible();
+    expect(window.location.pathname).toBe("/examples/ui");
+  });
+
+  it("reacts to demo sign-in and opens the protected integration route", async () => {
+    const user = userEvent.setup();
+    const authSession = createDemoSessionAdapter();
+    window.history.pushState({}, "", "/sample/resources");
+    render(<AppRouter authSession={authSession} />);
+
+    expect(
+      await screen.findByRole("heading", { name: "세션이 필요합니다." }),
+    ).toBeVisible();
+    await user.click(screen.getByRole("button", { name: "로그인 시작" }));
+
+    expect(
+      await screen.findByRole("heading", { name: "보호된 연동 지점" }),
+    ).toBeVisible();
+    expect(screen.getByText("인증됨")).toBeVisible();
+  });
+
+  it("fails closed when the auth integration does not change state", async () => {
+    const user = userEvent.setup();
     window.history.pushState({}, "", "/sample/resources");
     render(<AppRouter authSession={createAnonymousSessionAdapter()} />);
-    expect(screen.getByRole("heading", { name: "세션이 필요합니다." })).toBeVisible();
-    expect(screen.getByRole("button", { name: "로그인" })).toBeVisible();
+
+    await user.click(
+      await screen.findByRole("button", { name: "로그인 시작" }),
+    );
+
+    expect(
+      screen.getByRole("heading", { name: "세션이 필요합니다." }),
+    ).toBeVisible();
   });
 });