[Feature Request] 啥时候支持下聊天框发送文件

### 🥰 Feature Description

啥时候能支持下聊天框发送文件

### 🧐 Proposed Solution

支持本就能上传文件的模型发送文件聊天

### 📝 Additional Information

_No response_

The issue names no files, tests, or entry points. Start by locating the chat composer and the model-specific file-upload handling, then determine how uploads are represented and passed through the application. Done means the chat box can send files to models that already support file uploads, with coverage for the supported flow.

Written by the indexing model from the issue text.