fix(bt): honor selected files when creating resolved tasks (#1523)

ui/flutter/lib/features/tasks/domain/task_record.dart

@@ -36,8 +36,15 @@ enum TaskAssetType {
 }
 
 class TaskFileNode {
-  const TaskFileNode({required this.path, required this.name, required this.sizeBytes, this.downloadedBytes});
+  const TaskFileNode({
+    required this.path,
+    required this.name,
+    required this.sizeBytes,
+    this.downloadedBytes,
+    this.resourceIndex,
+  });
 
+  final int? resourceIndex;
   final String path;
   final String name;
   final int sizeBytes;
@@ -146,7 +153,7 @@ class TaskRecord {
       totalBytes: totalBytes > 0 ? totalBytes : null,
       speedBytes: task.progress.speed,
       uploadedBytes: task.progress.uploaded,
-      files: _fileNodes(task.meta.res?.files),
+      files: _fileNodes(task.meta.res?.files, task.meta.opts.selectFiles),
       uploading: task.uploading,
       isFolder: task.meta.res?.name.isNotEmpty ?? false,
       protocol: task.protocol,
@@ -314,12 +321,23 @@ int? _remainingSeconds(api_task.Task task, int totalBytes, int downloadedBytes)
   return ((totalBytes - downloadedBytes) / speed).ceil();
 }
 
-List<TaskFileNode> _fileNodes(List<api_resource.FileInfo>? files) {
+List<TaskFileNode> _fileNodes(List<api_resource.FileInfo>? files, List<int> selectedIndexes) {
   if (files == null || files.isEmpty) {
     return const [];
   }
+  final selected = selectedIndexes.toSet();
   return files
-      .map((file) => TaskFileNode(path: file.path, name: file.name, sizeBytes: file.size))
+      .asMap()
+      .entries
+      .where((entry) => selected.isEmpty || selected.contains(entry.key))
+      .map(
+        (entry) => TaskFileNode(
+          resourceIndex: entry.key,
+          path: entry.value.path,
+          name: entry.value.name,
+          sizeBytes: entry.value.size,
+        ),
+      )
       .toList(growable: false);
 }
 

ui/flutter/lib/features/tasks/presentation/widgets/task_file_tree.dart

@@ -77,7 +77,7 @@ class _TaskFileTreeState extends State<TaskFileTree> {
         .entries
         .map(
           (entry) => FileTreeItem<TaskFileNode>(
-            key: entry.key.toString(),
+            key: (entry.value.resourceIndex ?? entry.key).toString(),
             path: entry.value.path,
             name: entry.value.name,
             size: entry.value.sizeBytes,

ui/flutter/test/features/tasks/domain/task_record_test.dart

@@ -1,8 +1,48 @@
 import 'package:flutter_test/flutter_test.dart';
+import 'package:gopeed/api/model/task.dart' as api;
 import 'package:gopeed/core/icons/gopeed_icons.dart';
 import 'package:gopeed/features/tasks/domain/task_record.dart';
 
 void main() {
+  api.Task buildTask(List<int> selection, int size) => api.Task.fromJson({
+    'id': 'bt-selection',
+    'name': 'bundle',
+    'protocol': 'bt',
+    'status': 'running',
+    'uploading': false,
+    'createdAt': '2026-01-01T00:00:00Z',
+    'updatedAt': '2026-01-01T00:00:00Z',
+    'meta': {
+      'req': {'url': 'magnet:?xt=urn:btih:test'},
+      'opts': {'path': '/downloads', 'selectFiles': selection},
+      'res': {
+        'name': 'bundle',
+        'size': size,
+        'files': [
+          {'name': 'a.txt', 'size': 10},
+          {'name': 'b.txt', 'size': 20},
+          {'name': 'c.txt', 'path': 'nested', 'size': 30},
+        ],
+      },
+    },
+    'progress': {'used': 0, 'speed': 0, 'downloaded': 10, 'uploadSpeed': 0, 'uploaded': 0},
+  });
+
+  test('selected files retain original indexes for runtime progress', () {
+    final record = TaskRecord.fromApi(buildTask([2, 0], 40));
+    expect(record.files.map((file) => file.name), ['a.txt', 'c.txt']);
+    expect(record.files.map((file) => file.resourceIndex), [0, 2]);
+    expect(record.files.last.path, 'nested');
+    expect(record.totalBytes, 40);
+    expect(record.progress, 0.25);
+  });
+
+  test('empty selection preserves default all files', () {
+    final record = TaskRecord.fromApi(buildTask([], 60));
+    expect(record.files.length, 3);
+    expect(record.totalBytes, 60);
+  });
+
   test('file names preserve hash and question mark characters for type detection', () {
     expect(
       taskFileTypeIcon('Slow English Podcast #2 _ Eating, Talking, and Learning Natural English.mp4'),