feat: persistent photo job queue, worker, history with rollback

- Replace in-memory photoAiJobs Map with DB-backed photo_jobs table
- Background photo worker (worker.js) with retry, backoff, stale reset
  - Handles both AI (Real-ESRGAN) and server-side (sharp) enhancement
  - Controlled via photo_worker_enabled setting
- Photo job history in enhance modal with before/after thumbnails + rollback
- Worker dashboard: photo jobs section with status counts, recent table,
  compare slider for before/after, rollback from worker UI
- New endpoints: /api/photo-jobs/status|wake|enabled|requeue-failed,
  /api/entries/:id/photo/jobs (history), .../rollback
- swapEntryPhotoFiles logs every mutation to photo_jobs table

public/journal.html

@@ -27,6 +27,7 @@
 .enhance-sliders { flex: 0 0 240px; display: flex; flex-direction: column; gap: 14px; }
 .enhance-sliders .settings-field input[type=range] { width: 100%; }
 .enhance-foot { justify-content: flex-end; gap: 8px; margin-top: 14px; }
+.photo-thumb { width: 56px; height: 56px; object-fit: cover; border-radius: 6px; border: 1px solid var(--border); display: block; }
 @media (max-width: 800px) {
   .enhance-body { flex-direction: column; }
   .enhance-sliders { flex: 1 1 auto; display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); }
@@ -215,6 +216,7 @@
       </div>
     </div>
     <div class="card-foot enhance-foot">
+      <button type="button" class="btn-primary ghost" id="enhanceHistoryBtn" title="История изменений фотографии">🕘 История</button>
       <button type="button" class="btn-primary ghost" id="enhanceRestoreBtn" style="display:none" title="Вернуть исходную фотографию">↩ Вернуть оригинал</button>
       <button type="button" class="btn-primary ghost" id="enhanceAiBtn" style="display:none" title="ИИ-восстановление (Real-ESRGAN)">🤖 ИИ</button>
       <button type="button" class="btn-primary ghost" id="enhanceAutoBtn" title="Подобрать настройки автоматически">✨ Авто</button>
@@ -224,6 +226,16 @@
   </div>
 </div>
 
+<div class="modal-overlay" id="photoHistoryModal">
+  <div class="edit-modal enhance-modal">
+    <h3 id="photoHistoryTitle">История изменений фотографии</h3>
+    <div id="photoHistoryList" style="display:flex;flex-direction:column;gap:12px;max-height:60vh;overflow:auto"></div>
+    <div class="card-foot enhance-foot">
+      <button type="button" class="btn-primary ghost" id="photoHistoryCloseBtn">Закрыть</button>
+    </div>
+  </div>
+</div>
+
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
 <script src="admin.js"></script>