Add backend unit test framework and modularize settings UI

Introduced a Vitest-based backend unit testing framework with supporting scripts, helpers, and GitHub Actions integration. Refactored the admin settings page to a modular architecture, splitting monolithic logic into feature-specific tabs and hooks for improved maintainability and testability. Updated documentation to reflect the new testing setup and settings architecture, and added new dependencies for testing utilities.

tests/api/auth-misc.routes.test.ts

@@ -0,0 +1,120 @@
+/**
+ * Component: Auth Misc API Route Tests
+ * Documentation: documentation/testing.md
+ */
+
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { createPrismaMock } from '../helpers/prisma';
+
+let authRequest: any;
+
+const prismaMock = createPrismaMock();
+const requireAuthMock = vi.hoisted(() => vi.fn());
+const verifyRefreshTokenMock = vi.hoisted(() => vi.fn());
+const generateAccessTokenMock = vi.hoisted(() => vi.fn());
+const configServiceMock = vi.hoisted(() => ({
+  get: vi.fn(),
+}));
+
+vi.mock('@/lib/db', () => ({
+  prisma: prismaMock,
+}));
+
+vi.mock('@/lib/middleware/auth', () => ({
+  requireAuth: requireAuthMock,
+}));
+
+vi.mock('@/lib/utils/jwt', () => ({
+  verifyRefreshToken: verifyRefreshTokenMock,
+  generateAccessToken: generateAccessTokenMock,
+}));
+
+vi.mock('@/lib/services/config.service', () => ({
+  ConfigurationService: class {
+    get = configServiceMock.get;
+  },
+}));
+
+describe('Auth misc routes', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    authRequest = {
+      user: { id: 'user-1', role: 'user' },
+    };
+    requireAuthMock.mockImplementation((_req: any, handler: any) => handler(authRequest));
+    delete process.env.DISABLE_LOCAL_LOGIN;
+  });
+
+  it('logs out successfully', async () => {
+    const { POST } = await import('@/app/api/auth/logout/route');
+
+    const response = await POST();
+    const payload = await response.json();
+
+    expect(response.status).toBe(200);
+    expect(payload.success).toBe(true);
+  });
+
+  it('returns current user details with local admin flag', async () => {
+    prismaMock.user.findUnique.mockResolvedValue({
+      id: 'user-1',
+      plexId: 'local-admin',
+      plexUsername: 'admin',
+      plexEmail: 'admin@example.com',
+      role: 'admin',
+      isSetupAdmin: true,
+      avatarUrl: null,
+      authProvider: 'local',
+      createdAt: new Date(),
+      lastLoginAt: new Date(),
+    });
+
+    const { GET } = await import('@/app/api/auth/me/route');
+    const response = await GET({} as any);
+    const payload = await response.json();
+
+    expect(payload.user.isLocalAdmin).toBe(true);
+    expect(payload.user.username).toBe('admin');
+  });
+
+  it('refreshes access token when refresh token is valid', async () => {
+    verifyRefreshTokenMock.mockReturnValue({ sub: 'user-1' });
+    prismaMock.user.findUnique.mockResolvedValue({
+      id: 'user-1',
+      plexId: 'plex-1',
+      plexUsername: 'user',
+      role: 'user',
+    });
+    generateAccessTokenMock.mockReturnValue('access-token');
+
+    const { POST } = await import('@/app/api/auth/refresh/route');
+    const response = await POST({ json: vi.fn().mockResolvedValue({ refreshToken: 'refresh' }) } as any);
+    const payload = await response.json();
+
+    expect(response.status).toBe(200);
+    expect(payload.accessToken).toBe('access-token');
+  });
+
+  it('returns provider info for audiobookshelf mode', async () => {
+    configServiceMock.get
+      .mockResolvedValueOnce('audiobookshelf')
+      .mockResolvedValueOnce('prowlarr')
+      .mockResolvedValueOnce('http://prowlarr')
+      .mockResolvedValueOnce('true')
+      .mockResolvedValueOnce('true')
+      .mockResolvedValueOnce('MyOIDC');
+
+    prismaMock.user.count.mockResolvedValueOnce(1);
+
+    const { GET } = await import('@/app/api/auth/providers/route');
+    const response = await GET();
+    const payload = await response.json();
+
+    expect(payload.backendMode).toBe('audiobookshelf');
+    expect(payload.providers).toContain('oidc');
+    expect(payload.registrationEnabled).toBe(true);
+    expect(payload.oidcProviderName).toBe('MyOIDC');
+  });
+});
+
+