feat(v029): m004 마이그레이션 — status/status_changed_at/move_reason 컬럼

- notes 테이블 ADD COLUMN status (DEFAULT 'active'), status_changed_at, move_reason
- deleted_at != NULL 노트 → status='trashed' + status_changed_at=deleted_at 로 backfill
- index.ts registry 에 m004 추가 (runMigrations 자동 적용)
- migrations.test.ts user_version assertion 4 로 갱신

src/main/db/migrations/index.ts

@@ -2,8 +2,9 @@ import type Database from 'better-sqlite3';
 import * as m001 from './m001_initial.js';
 import * as m002 from './m002_due_date.js';
 import * as m003 from './m003_soft_delete.js';
+import * as m004 from './m004_status.js';
 
-const migrations = [m001, m002, m003];
+const migrations = [m001, m002, m003, m004];
 
 export function latestVersion(): number {
   return migrations[migrations.length - 1]!.version;

src/main/db/migrations/m004_status.ts

@@ -0,0 +1,18 @@
+// v4: status 4분기 (active/completed/archived/trashed) + 사유 + status_changed_at.
+// 기존 deleted_at != NULL 노트는 status='trashed' 로 migrate. deleted_at 컬럼은
+// backward compat 위해 잔류 (status='trashed' 와 동기화). 향후 cut 에서 제거 가능.
+import type Database from 'better-sqlite3';
+
+export const version = 4;
+
+export function up(db: Database.Database): void {
+  db.exec(`
+    ALTER TABLE notes ADD COLUMN status TEXT NOT NULL DEFAULT 'active';
+    ALTER TABLE notes ADD COLUMN status_changed_at TEXT;
+    ALTER TABLE notes ADD COLUMN move_reason TEXT;
+  `);
+  db.prepare(
+    `UPDATE notes SET status='trashed', status_changed_at=deleted_at
+     WHERE deleted_at IS NOT NULL`
+  ).run();
+}

tests/unit/m004-migration.test.ts

@@ -0,0 +1,80 @@
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import Database from 'better-sqlite3';
+import { up } from '../../src/main/db/migrations/m004_status.js';
+
+describe('m004 migration — status column', () => {
+  let db: Database.Database;
+
+  beforeEach(() => {
+    db = new Database(':memory:');
+    // m003 baseline (notes 테이블 with deleted_at, real schema 따름)
+    db.exec(`
+      CREATE TABLE notes (
+        id                       TEXT PRIMARY KEY,
+        raw_text                 TEXT NOT NULL,
+        ai_title                 TEXT,
+        ai_summary               TEXT,
+        ai_status                TEXT NOT NULL
+                                 CHECK (ai_status IN ('pending','done','failed')),
+        ai_error                 TEXT,
+        ai_provider              TEXT,
+        ai_generated_at          TEXT,
+        title_edited_by_user     INTEGER NOT NULL DEFAULT 0,
+        summary_edited_by_user   INTEGER NOT NULL DEFAULT 0,
+        user_intent              TEXT,
+        intent_prompted_at       TEXT,
+        created_at               TEXT NOT NULL,
+        updated_at               TEXT NOT NULL,
+        due_date                 TEXT,
+        due_date_edited_by_user  INTEGER NOT NULL DEFAULT 0,
+        deleted_at               TEXT,
+        last_recalled_at         TEXT,
+        recall_dismissed_at      TEXT
+      );
+      INSERT INTO notes (id, raw_text, ai_status, created_at, updated_at, deleted_at)
+        VALUES ('a', 't1', 'done', '2026-05-01T00:00:00Z', '2026-05-01T00:00:00Z', NULL),
+               ('b', 't2', 'done', '2026-05-01T00:00:00Z', '2026-05-01T00:00:00Z', '2026-05-08T00:00:00Z');
+    `);
+  });
+
+  afterEach(() => {
+    db.close();
+  });
+
+  it('adds status / status_changed_at / move_reason columns', () => {
+    up(db);
+    const cols = db.prepare(`PRAGMA table_info(notes)`).all() as Array<{ name: string }>;
+    const names = cols.map((c) => c.name);
+    expect(names).toContain('status');
+    expect(names).toContain('status_changed_at');
+    expect(names).toContain('move_reason');
+  });
+
+  it('default status="active" for non-deleted notes', () => {
+    up(db);
+    const a = db.prepare(`SELECT status FROM notes WHERE id=?`).get('a') as { status: string };
+    expect(a.status).toBe('active');
+  });
+
+  it('migrates deleted_at != NULL to status="trashed" + status_changed_at', () => {
+    up(db);
+    const b = db
+      .prepare(`SELECT status, status_changed_at FROM notes WHERE id=?`)
+      .get('b') as { status: string; status_changed_at: string };
+    expect(b.status).toBe('trashed');
+    expect(b.status_changed_at).toBe('2026-05-08T00:00:00Z');
+  });
+
+  it('move_reason NULL by default', () => {
+    up(db);
+    const a = db.prepare(`SELECT move_reason FROM notes WHERE id=?`).get('a') as {
+      move_reason: string | null;
+    };
+    expect(a.move_reason).toBeNull();
+  });
+
+  it('version exported as 4', async () => {
+    const mod = await import('../../src/main/db/migrations/m004_status.js');
+    expect(mod.version).toBe(4);
+  });
+});

tests/unit/migrations.test.ts

@@ -51,11 +51,11 @@ describe('migration v3 — soft delete columns', () => {
     db.close();
   });
 
-  it('user_version reaches 3', () => {
+  it('user_version reaches 4', () => {
     const db = new Database(':memory:');
     runMigrations(db);
     const row = db.prepare('PRAGMA user_version').get() as { user_version: number };
-    expect(row.user_version).toBe(3);
+    expect(row.user_version).toBe(4);
     db.close();
   });