perf(travel-proxy): 배치 DB 연결 + nginx sync timeout 600s

- db.py: batch_sync_album, batch_mark_thumbs_done 추가
- indexer.py: 앨범 단위 배치 동기화로 전환
- nginx: /api/travel/ proxy_read_timeout 600s 추가

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

travel-proxy/app/indexer.py

@@ -92,7 +92,7 @@ def sync(
         elif isinstance(v, dict) and isinstance(v.get("albums"), list):
             all_albums.update(v["albums"])
 
-    # 2. 각 앨범 폴더 스캔 → DB 동기화
+    # 2. 각 앨범 폴더 스캔 → DB 배치 동기화
     added = 0
     updated = 0
     removed = 0
@@ -100,29 +100,27 @@ def sync(
     for album in sorted(all_albums):
         folder = travel_root / album
         items = _scan_folder(folder)
-        existing_filenames = set()
+        existing_filenames = {item["filename"] for item in items}
 
-        for item in items:
-            existing_filenames.add(item["filename"])
-            result = db.upsert_photo(album, item["filename"], item["mtime"])
-            if result == "added":
-                added += 1
-            elif result == "updated":
-                updated += 1
-
-        removed += db.remove_missing_photos(album, existing_filenames)
+        result = db.batch_sync_album(album, items, existing_filenames)
+        added += result["added"]
+        updated += result["updated"]
+        removed += result["removed"]
 
     # 3. 썸네일 미생성 분 일괄 생성
     no_thumb = db.get_photos_without_thumb()
     thumbs_generated = 0
+    thumb_done_batch = []
 
     for photo in no_thumb:
         src = travel_root / photo["album"] / photo["filename"]
         dest = thumb_root / photo["album"] / photo["filename"]
         if _generate_thumb(src, dest):
-            db.mark_thumb_done(photo["album"], photo["filename"])
+            thumb_done_batch.append(photo)
             thumbs_generated += 1
 
+    db.batch_mark_thumbs_done(thumb_done_batch)
+
     duration = round(time.time() - start, 2)
     logger.info(
         "Sync complete: added=%d updated=%d removed=%d thumbs=%d duration=%.2fs",