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/lib/stores/__tests__/draft-store.test.ts

@@ -0,0 +1,71 @@
+// File: frontend/lib/stores/__tests__/draft-store.test.ts
+// Change Log:
+// - 2026-06-13: Initial creation - test coverage for useDraftStore (Zustand)
+
+import { describe, it, expect, beforeEach } from 'vitest';
+import { act, renderHook } from '@testing-library/react';
+import { useDraftStore } from '../draft-store';
+
+describe('useDraftStore', () => {
+  beforeEach(() => {
+    // รีเซ็ต store ก่อนแต่ละ test
+    act(() => {
+      useDraftStore.setState({ drafts: {} });
+    });
+  });
+
+  it('ค่า default ควรเป็น drafts: {}', () => {
+    const { result } = renderHook(() => useDraftStore());
+    expect(result.current.drafts).toEqual({});
+  });
+
+  it('saveDraft ควรบันทึก draft data ด้วย key ที่กำหนด', () => {
+    const { result } = renderHook(() => useDraftStore());
+    const draftData = { title: 'Test Document', projectId: '019505a1-7c3e-7000-8000-abc123def456' };
+    act(() => {
+      result.current.saveDraft('rfa-new', draftData);
+    });
+    expect(result.current.drafts['rfa-new']).toEqual(draftData);
+  });
+
+  it('getDraft ควรดึงข้อมูล draft ตาม key', () => {
+    const { result } = renderHook(() => useDraftStore());
+    const draftData = { subject: 'Correspondence Test', content: 'Body text' };
+    act(() => {
+      result.current.saveDraft('corr-edit', draftData);
+    });
+    const retrieved = result.current.getDraft('corr-edit');
+    expect(retrieved).toEqual(draftData);
+  });
+
+  it('getDraft ควร return undefined หาก key ไม่มีใน store', () => {
+    const { result } = renderHook(() => useDraftStore());
+    const retrieved = result.current.getDraft('non-existent-key');
+    expect(retrieved).toBeUndefined();
+  });
+
+  it('clearDraft ควรลบ draft ออกตาม key', () => {
+    const { result } = renderHook(() => useDraftStore());
+    act(() => {
+      result.current.saveDraft('rfa-draft', { title: 'To Delete' });
+    });
+    expect(result.current.drafts['rfa-draft']).toBeDefined();
+    act(() => {
+      result.current.clearDraft('rfa-draft');
+    });
+    expect(result.current.drafts['rfa-draft']).toBeUndefined();
+  });
+
+  it('saveDraft ไม่ควรลบ draft อื่นที่ไม่ใช่ key เดียวกัน', () => {
+    const { result } = renderHook(() => useDraftStore());
+    act(() => {
+      result.current.saveDraft('key-a', { data: 'A' });
+      result.current.saveDraft('key-b', { data: 'B' });
+    });
+    act(() => {
+      result.current.clearDraft('key-a');
+    });
+    expect(result.current.drafts['key-a']).toBeUndefined();
+    expect(result.current.drafts['key-b']).toEqual({ data: 'B' });
+  });
+});