照片列表支持分页

bin/domain/repositories/photo_repository.dart

@@ -4,6 +4,7 @@ import 'dart:typed_data';
 
 import 'package:path/path.dart' as p;
 import '../entities/photo.dart';
+import '../page_result.dart';
 
 class PhotoRepository {
   final String basePath;
@@ -12,7 +13,30 @@ class PhotoRepository {
 
   PhotoRepository(this.basePath);
 
+  /// 获取相册中所有照片（不分页，保留兼容）
   Future<List<Photo>> getPhotosByAlbumId(int id) async {
+    final all = await _loadPhotosForAlbum(id);
+    return all;
+  }
+
+  /// 获取相册中的照片（分页）
+  Future<PageResult<Photo>> getPhotosByAlbumIdPaged(
+    int id, {
+    int page = 1,
+    int size = 20,
+  }) async {
+    final all = await _loadPhotosForAlbum(id);
+    final total = all.length;
+    final startIndex = (page - 1) * size;
+    final endIndex = startIndex + size;
+    final items = startIndex < total
+        ? all.sublist(startIndex, endIndex > total ? total : endIndex)
+        : <Photo>[];
+    return PageResult(items: items, total: total, page: page, size: size);
+  }
+
+  /// 内部方法：加载相册照片（带缓存）
+  Future<List<Photo>> _loadPhotosForAlbum(int id) async {
     if (_updatedMap.containsKey(id) &&
         DateTime.now().difference(_updatedMap[id]!).inSeconds <= 60) {
       return _map[id]!;