[BUG] Web Interface: Uploaded files (images/docs) in history chats are inaccessible/unclickable

When using the web version,describe the bug
I can see the icons of files (images, .txt, .docx) I uploaded in past conversations, but they are completely unclickable and inaccessible. I cannot preview or download them, even though they were correctly processed by the model during the initial conversation. This leads to a severe loss of creative assets and reference materials.

To Reproduce
Open a historical chat session in DeepSeek Web.

Locate any previously uploaded file (e.g., a screenshot or a document).

Attempt to click on the file icon to preview or download it.

Observe that there is no response, or the file fails to load.

Expected behavior
Users should be able to click on historical attachments to preview the content or re-download the files, ensuring the continuity of the creative workflow and data integrity.

Screenshots

Additional context
I am a scenario writer using DeepSeek for logic-heavy scriptwriting. These lost files are critical assets that weren't backed up locally. This issue creates significant "logic gaps" in my project data and disrupts my preparation for upcoming milestones.

Update: I tried to inspect the source code. The file icons are rendering with blob: URLs or placeholder text, but the original file links seem to be broken or expired on the server-side. This is NOT a "privacy policy" issue (I can still see my text history from 2025), but a technical storage/retrieval bug.

Critical Technical Evidence:
I found several CORS policy blocking errors and 503 Service Unavailable errors in the browser console when attempting to access uploaded files (both in history and new chats).

Request URL: [https://files.deepseek.com/] (https://files.deepseek.com/)...

Error: No 'Access-Control-Allow-Origin' header is present on the requested resource.
This confirms it's a server-side configuration issue or a service outage, not a client-side problem or a policy-based restriction.

Even before the conversation was sent, I found that files could not be opened or read when uploading them. This is a significant vulnerability when checking context before the conversation is sent. I suspect this isn't a setting issue, but a very serious bug that you need to fix as soon as possible. Hopefully, this isn't due to a problem with your server.

故障描述 (Bug Description)
在网页版使用过程中发现的故障：
我可以在历史对话中看到之前上传的文件图标（包括图片、.txt、.docx 等），但它们现在完全无法点击，也无法访问。即使在初始对话时这些文件已被模型正确处理，现在也无法进行预览或下载。这导致我严重的创作资产和参考资料丢失。

复现步骤 (To Reproduce)
打开 DeepSeek 网页端的历史对话会话。

找到任何之前上传的文件（例如截图或文档）。

尝试点击文件图标进行预览或下载。

观察到系统没有任何响应，或者文件加载失败。

预期行为 (Expected Behavior)
用户应当能够点击历史附件来预览内容或重新下载文件，以确保创作工作流的连续性和数据的完整性。

补充上下文 (Additional Context)
我是一名剧本创作者，使用 DeepSeek 进行高逻辑要求的脚本编写工作。这些丢失的文件是极其关键的资产，且未在本地备份。该问题导致我的项目数据出现了严重的“逻辑断层”，并干扰了我对后续重要节点的准备工作。

更新 (Update)：
我尝试检查了源代码。文件图标通过 blob: URLs 或占位符文本渲染，但原始文件链接似乎在服务器端已断开或过期。这并非“隐私政策”问题（因为我仍能查看 2025 年的文字历史），而是一个纯粹的技术性存储/读取 Bug。

关键技术证据 (Critical Technical Evidence)
在尝试访问上传的文件（包括历史记录和新对话）时，我在浏览器控制台中发现了多项 CORS 跨域策略拦截错误和 503 (Service Unavailable) 服务不可用错误。

请求 URL (Request URL): [https://files.deepseek.com/] (https://files.deepseek.com/)...

错误信息 (Error): No 'Access-Control-Allow-Origin' header is present on the requested resource.

这证实了该问题是服务器端的配置错误或服务宕机所致，而非客户端问题，也不是基于政策的限制。

甚至在对话发送之前，我就发现上传的文件无法被打开或读取。在发送对话前检查上下文时，这是一个严重的漏洞。我怀疑这并非设置问题，而是一个需要尽快修复的严重 Bug。希望这不会是因为贵方服务器出现了不可逆的故障。

为了方便国内技术团队更直观地复现和排查，我补充了上述内容的中文书面版本。再次感谢你们的重视和帮助。