Add unit tests for Admin pages: Settings, Users, and Organizations

- Implemented rendering tests for titles, descriptions, placeholders, and feature lists.
- Verified proper container structure and navigation links for each admin page.

frontend/tests/app/admin/settings/page.test.tsx

@@ -0,0 +1,66 @@
+/**
+ * Tests for Admin Settings Page
+ * Verifies rendering of system settings placeholder
+ */
+
+import { render, screen } from '@testing-library/react';
+import AdminSettingsPage from '@/app/admin/settings/page';
+
+describe('AdminSettingsPage', () => {
+  it('renders page title', () => {
+    render(<AdminSettingsPage />);
+
+    expect(screen.getByText('System Settings')).toBeInTheDocument();
+  });
+
+  it('renders page description', () => {
+    render(<AdminSettingsPage />);
+
+    expect(
+      screen.getByText('Configure system-wide settings and preferences')
+    ).toBeInTheDocument();
+  });
+
+  it('renders back button link', () => {
+    render(<AdminSettingsPage />);
+
+    const backLink = screen.getByRole('link', { name: '' });
+    expect(backLink).toHaveAttribute('href', '/admin');
+  });
+
+  it('renders coming soon message', () => {
+    render(<AdminSettingsPage />);
+
+    expect(
+      screen.getByText('System Settings Coming Soon')
+    ).toBeInTheDocument();
+  });
+
+  it('renders feature list', () => {
+    render(<AdminSettingsPage />);
+
+    expect(
+      screen.getByText(/General system configuration/)
+    ).toBeInTheDocument();
+    expect(
+      screen.getByText(/Email and notification settings/)
+    ).toBeInTheDocument();
+    expect(
+      screen.getByText(/Security and authentication options/)
+    ).toBeInTheDocument();
+    expect(
+      screen.getByText(/API and integration settings/)
+    ).toBeInTheDocument();
+    expect(
+      screen.getByText(/Maintenance and backup tools/)
+    ).toBeInTheDocument();
+  });
+
+  it('renders with proper container structure', () => {
+    const { container } = render(<AdminSettingsPage />);
+
+    const containerDiv = container.querySelector('.container');
+    expect(containerDiv).toBeInTheDocument();
+    expect(containerDiv).toHaveClass('mx-auto', 'px-6', 'py-8');
+  });
+});