### What problem does this PR solve?
- [x] New Feature (non-breaking change which adds functionality)
---------
Co-authored-by: Yingfeng <yingfeng.zhang@gmail.com>
Co-authored-by: Jin Hai <haijin.chn@gmail.com>
https://github.com/infiniflow/ragflow/issues/3651
### What problem does this PR solve?
_Briefly describe what this PR aims to solve. Include background context
that will help reviewers understand the purpose of the PR._
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)
### What problem does this PR solve?
fix: reference file with 'docx' type can not open #844
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)
### What problem does this PR solve?
feat: change all file names to lowercase #1574
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
fix: display specific error message when previewing file error #868
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)
### What problem does this PR solve?
fix: remove Top K in retrieval testing #770
fix: if the document parsing fails, the error message returned by the
backend is displayed.
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)
### What problem does this PR solve?
feat: delete the added model #503
feat: display an error message when the requested file fails to parse
#684
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
fix: fix uploaded file time error #680
feat: support preview of word and excel #684
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)
### What problem does this PR solve?
#666
feat: support DeepSeek
feat: preview word and excel
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
