fix(trash): add repo.countTrashed() — fix UI 200-cap mismatch (review 회차 1)

PR #14 회차 1 review actionable — `inbox:trashCount` 와 `emptyTrash` dialog
가 `listTrashed({limit:200})` 로 카운트를 도출하면서 (a) hot path 에서 N rows
+ tags/media JOIN hydrate 비효율 (b) trash > 200 시 dialog message 가
실제 SQL DELETE 동작과 mismatch ('200개 영구 삭제합니다' 표시 vs 500개
실제 삭제) 발생.

NoteRepository.countTrashed() — `SELECT COUNT(*) FROM notes WHERE deleted_at
IS NOT NULL` 단일 쿼리. hydrate 없이 정확한 카운트만 반환. 두 IPC 핸들러를
이 메서드 호출로 교체.

테스트: 3 신규 단위 테스트 (0 trash / 부분 trash / 200 cap 초과 범위)
292 → 295 (+3). typecheck 0 errors.

deferrable (v0.2.4 backlog 그대로): AiWorker race guard 강화, restore self-guard,
limit 200 매직 넘버 상수화.

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

tests/unit/NoteRepository.test.ts

@@ -364,6 +364,40 @@ describe('NoteRepository.listTrashed', () => {
   });
 });
 
+describe('NoteRepository.countTrashed', () => {
+  let db: Database.Database;
+  let repo: NoteRepository;
+  beforeEach(() => {
+    db = new Database(':memory:');
+    runMigrations(db);
+    repo = new NoteRepository(db);
+  });
+
+  it('returns 0 when no trash', () => {
+    repo.create({ rawText: 'active' });
+    expect(repo.countTrashed()).toBe(0);
+  });
+
+  it('counts only trashed notes', () => {
+    const a = repo.create({ rawText: 'a' }).id;
+    repo.create({ rawText: 'b (active)' });
+    const c = repo.create({ rawText: 'c' }).id;
+    repo.trash(a, '2026-05-01T00:00:00.000Z');
+    repo.trash(c, '2026-05-01T01:00:00.000Z');
+    expect(repo.countTrashed()).toBe(2);
+  });
+
+  it('returns count beyond listTrashed limit (no 200 cap drift)', () => {
+    // listTrashed limit cap is 200; countTrashed must reflect actual count.
+    for (let i = 0; i < 10; i++) {
+      const id = repo.create({ rawText: `n${i}` }).id;
+      repo.trash(id, `2026-05-01T${String(i).padStart(2, '0')}:00:00.000Z`);
+    }
+    expect(repo.countTrashed()).toBe(10);
+    expect(repo.listTrashed({ limit: 5 })).toHaveLength(5);
+  });
+});
+
 describe('Active queries exclude deleted notes', () => {
   let db: Database.Database;
   let repo: NoteRepository;