Update admin theme/layout and refresh README details.

Align the project baseline with the latest admin interface styling and layout structure while documenting setup and usage updates in README.

apps/web/src/modules/content/api/contentApi.test.ts

@@ -0,0 +1,53 @@
+import { describe, expect, it, vi } from "vitest";
+import {
+  createContentPage,
+  deleteContentPage,
+  getAdminPages,
+  getPageBySlug,
+  updateContentPage
+} from "./contentApi";
+
+vi.mock("@shared/api/client", () => ({
+  apiClient: {
+    get: vi.fn(async (url: string) => {
+      if (url === "/api/v1/content/pages/manage/all") {
+        return { data: { data: [{ id: "1", slug: "about", title: "About", body: "", status: "published" }] } };
+      }
+      return { data: { slug: "about", title: "About" } };
+    }),
+    post: vi.fn(async () => ({ data: { id: "2", slug: "new", title: "New", body: "", status: "draft" } })),
+    patch: vi.fn(async () => ({ data: { id: "1", slug: "about", title: "Updated", body: "", status: "published" } })),
+    delete: vi.fn(async () => ({ data: {} }))
+  }
+}));
+
+describe("contentApi", () => {
+  it("loads page by slug", async () => {
+    const data = await getPageBySlug("about");
+    expect(data.slug).toBe("about");
+  });
+
+  it("loads admin pages", async () => {
+    const pages = await getAdminPages();
+    expect(pages[0].slug).toBe("about");
+  });
+
+  it("creates content page", async () => {
+    const page = await createContentPage({
+      slug: "new",
+      title: "New",
+      body: "<p>x</p>",
+      status: "draft"
+    });
+    expect(page.slug).toBe("new");
+  });
+
+  it("updates content page", async () => {
+    const page = await updateContentPage("1", { title: "Updated" });
+    expect(page.title).toBe("Updated");
+  });
+
+  it("deletes content page", async () => {
+    await expect(deleteContentPage("1")).resolves.toBeUndefined();
+  });
+});