Bug: Group by date modified shows same year folders in last year group

### Description

如图这个是打开下载页面，这5个文件夹分类完全有问题，明明4个最新修改日期是今年的，但是分类却显示是去年的。

### Steps To Reproduce

1.打开
2.点击下载
3.拉到最下面

### Files Version

4.2.0.0

### Windows Version

10.0.26200.8655

### User ID

1e2c4650-e5db-4577-9e88-7c0a447107ee

### Log File

[debug.log](https://github.com/user-attachments/files/30366328/debug.log)

Reproduce the issue by opening Downloads, scrolling to the bottom, and grouping items by date modified; review the linked debug.log for relevant context. Done means folders modified this year appear in the current-year group rather than last year's group.

Written by the indexing model from the issue text.