feat(ai): add ADR-036 unified OCR architecture and frontend test coverage

- Add ADR-036 unified OCR architecture (typhoon-ocr via Ollama)
- Extend AI execution profiles for OCR sandbox configuration
- Add comprehensive frontend test coverage (components, hooks, services)
- Add backend test coverage for document-numbering services
- Update OCR sidecar with typhoon-ocr integration
- Add AI policy service and execution profile management
- Update AGENTS.md and architecture documentation

frontend/components/layout/__tests__/navbar.test.tsx

@@ -0,0 +1,71 @@
+// File: frontend/components/layout/__tests__/navbar.test.tsx
+// Change Log:
+// - 2026-06-13: Initial creation - test coverage for Navbar component
+
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { render, screen, fireEvent } from '@testing-library/react';
+import { act } from '@testing-library/react';
+import { Navbar } from '../navbar';
+import { useUIStore } from '@/lib/stores/ui-store';
+import { useSession } from 'next-auth/react';
+
+// Mock dependencies
+vi.mock('next-auth/react', () => ({
+  useSession: vi.fn(),
+  signOut: vi.fn(),
+}));
+
+vi.mock('next/navigation', () => ({
+  useRouter: () => ({ push: vi.fn() }),
+}));
+
+vi.mock('next/link', () => ({
+  default: ({ children, href }: { children: React.ReactNode; href: string }) => (
+    <a href={href}>{children}</a>
+  ),
+}));
+
+describe('Navbar', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    // รีเซ็ต ui store
+    act(() => {
+      useUIStore.setState({ isSidebarOpen: true, toggleSidebar: vi.fn() });
+    });
+    vi.mocked(useSession).mockReturnValue({
+      data: { user: { name: 'John Doe', email: 'john@example.com', role: 'Admin' } },
+    } as any);
+  });
+
+  it('ควรเรนเดอร์ header ได้ถูกต้อง', () => {
+    render(<Navbar />);
+    expect(screen.getByRole('banner')).toBeInTheDocument();
+  });
+
+  it('ควรแสดงข้อความ Document Management System', () => {
+    render(<Navbar />);
+    expect(screen.getByText('Document Management System')).toBeInTheDocument();
+  });
+
+  it('ควรมีปุ่ม Toggle navigation menu สำหรับ mobile', () => {
+    render(<Navbar />);
+    expect(screen.getByText('Toggle navigation menu')).toBeInTheDocument();
+  });
+
+  it('ควรมีปุ่ม Notifications', () => {
+    render(<Navbar />);
+    expect(screen.getByText('Notifications')).toBeInTheDocument();
+  });
+
+  it('ควรเรียก toggleSidebar เมื่อคลิกปุ่ม menu', () => {
+    const mockToggle = vi.fn();
+    act(() => {
+      useUIStore.setState({ isSidebarOpen: true, toggleSidebar: mockToggle });
+    });
+    render(<Navbar />);
+    // ปุ่ม menu บน mobile
+    const menuButton = screen.getByRole('button', { name: /toggle navigation menu/i });
+    fireEvent.click(menuButton);
+    expect(mockToggle).toHaveBeenCalledOnce();
+  });
+});