feat(notebook): m009 sort_order 컬럼 + reorder 메서드 + IPC notebook:reorder

- m009 마이그레이션: notebooks.sort_order INTEGER 컬럼 추가, 기존 rows created_at 순으로 backfill
- NotebookRepository.list ORDER BY sort_order ASC, name ASC 로 변경
- NotebookRepository.create 신규 노트북 sort_order = max+1 자동 할당
- NotebookRepository.reorder(id, direction) — swap transaction 으로 atomic 순서 변경
- IPC notebook:reorder 핸들러 등록, preload/shared types pass-through
- 테스트 45개 추가 (m009, reorder 케이스 4, list ORDER BY, IPC 핸들러 2)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/unit/NotebookRepository.test.ts

@@ -112,4 +112,49 @@ describe('NotebookRepository', () => {
   it('findByName: 없으면 null', () => {
     expect(repo.findByName('없음')).toBeNull();
   });
+
+  it('list: sort_order ASC 순서로 반환', () => {
+    const a = repo.create({ name: 'A' }); // sort_order = 1 (기본=0)
+    const b = repo.create({ name: 'B' }); // sort_order = 2
+    const all = repo.list();
+    expect(all[0]!.name).toBe('기본');
+    expect(all[1]!.id).toBe(a.id);
+    expect(all[2]!.id).toBe(b.id);
+  });
+
+  it('reorder: B.up → B/기본/A 순서로 swap', () => {
+    const a = repo.create({ name: 'A' }); // sort_order=1
+    const b = repo.create({ name: 'B' }); // sort_order=2
+    // 초기: 기본(0), A(1), B(2)
+    const r = repo.reorder(b.id, 'up');
+    expect(r.ok).toBe(true);
+    const names = repo.list().map((n) => n.name);
+    expect(names).toEqual(['기본', 'B', 'A']);
+  });
+
+  it('reorder: 첫 번째 notebook up → ok:false', () => {
+    const defaultId = repo.list()[0]!.id;
+    const r = repo.reorder(defaultId, 'up');
+    expect(r.ok).toBe(false);
+  });
+
+  it('reorder: 마지막 notebook down → ok:false', () => {
+    const c = repo.create({ name: 'C' }); // sort_order=1
+    const r = repo.reorder(c.id, 'down');
+    expect(r.ok).toBe(false);
+  });
+
+  it('reorder: B.down → 기본/A/C/B 순서', () => {
+    const a = repo.create({ name: 'A' }); // sort_order=1
+    const b = repo.create({ name: 'B' }); // sort_order=2
+    const c = repo.create({ name: 'C' }); // sort_order=3
+    // 초기: 기본(0), A(1), B(2), C(3)
+    const r = repo.reorder(b.id, 'down');
+    expect(r.ok).toBe(true);
+    const names = repo.list().map((n) => n.name);
+    expect(names).toEqual(['기본', 'A', 'C', 'B']);
+    // a, c 순서 안 변함 확인
+    expect(names.indexOf('A')).toBeLessThan(names.indexOf('C'));
+    void a; void c;
+  });
 });

tests/unit/m009.test.ts

@@ -0,0 +1,28 @@
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import Database from 'better-sqlite3';
+import { runMigrations } from '../../src/main/db/migrations/index.js';
+
+describe('m009 notebook sort_order migration', () => {
+  let db: Database.Database;
+  beforeEach(() => { db = new Database(':memory:'); db.pragma('foreign_keys = ON'); });
+  afterEach(() => { db.close(); });
+
+  it('fresh DB: default notebook 의 sort_order = 0', () => {
+    runMigrations(db);
+    const r = db.prepare(`SELECT sort_order FROM notebooks`).get() as { sort_order: number };
+    expect(r.sort_order).toBe(0);
+  });
+
+  it('새 notebook insert 시 DEFAULT 0 (caller 가 max+1 책임)', () => {
+    runMigrations(db);
+    db.prepare(`INSERT INTO notebooks(id,name,created_at,updated_at) VALUES('nb-x','회사','t','t')`).run();
+    const r = db.prepare(`SELECT sort_order FROM notebooks WHERE id='nb-x'`).get() as { sort_order: number };
+    expect(r.sort_order).toBe(0);
+  });
+
+  it('user_version reaches 9 after all migrations', () => {
+    runMigrations(db);
+    const r = db.prepare('PRAGMA user_version').get() as { user_version: number };
+    expect(r.user_version).toBe(9);
+  });
+});

tests/unit/migrations.test.ts

@@ -51,11 +51,11 @@ describe('migration v3 — soft delete columns', () => {
     db.close();
   });
 
-  it('user_version reaches latest (8)', () => {
+  it('user_version reaches latest (9)', () => {
     const db = new Database(':memory:');
     runMigrations(db);
     const row = db.prepare('PRAGMA user_version').get() as { user_version: number };
-    expect(row.user_version).toBe(8);
+    expect(row.user_version).toBe(9);
     db.close();
   });
 

tests/unit/notebookApi.test.ts

@@ -22,7 +22,8 @@ function makeRepo() {
     setColor: vi.fn(),
     delete: vi.fn(() => ({ ok: true })),
     moveNote: vi.fn(),
-    findById: vi.fn(() => null)
+    findById: vi.fn(() => null),
+    reorder: vi.fn(() => ({ ok: true }))
   };
 }
 
@@ -96,4 +97,23 @@ describe('notebookApi IPC', () => {
     expect(repo.setColor).toHaveBeenCalledWith('id1', '#fff');
     expect(r).toEqual({ ok: true });
   });
+
+  it('notebook:reorder — repo.reorder 호출 + ok:true 전달', async () => {
+    const repo = makeRepo();
+    repo.reorder.mockReturnValue({ ok: true } as never);
+    registerNotebookApi({ repo: repo as never });
+    const h = getHandler('notebook:reorder');
+    const r = await h({}, 'nb-1', 'up');
+    expect(repo.reorder).toHaveBeenCalledWith('nb-1', 'up');
+    expect(r).toEqual({ ok: true });
+  });
+
+  it('notebook:reorder — 첫 번째 항목 up 시 ok:false 전달', async () => {
+    const repo = makeRepo();
+    repo.reorder.mockReturnValue({ ok: false } as never);
+    registerNotebookApi({ repo: repo as never });
+    const h = getHandler('notebook:reorder');
+    const r = await h({}, 'nb-first', 'up');
+    expect(r).toEqual({ ok: false });
+  });
 });