"Content-Disposition" Header set in view_image function not matching RFC2183 rules

### Custom Node Testing

- [x] I have tried disabling custom nodes and the issue persists (see [how to disable custom nodes](https://docs.comfy.org/troubleshooting/custom-node-issues#step-1%3A-test-with-all-custom-nodes-disabled) if you need help)

### Expected Behavior

When a file is fetched from ComfyUI via the [view_image](https://github.com/comfyanonymous/ComfyUI/blob/master/server.py#L421) function, the "Content-Disposition" response header will be set to something like `filename=name.ext`, which doesn't match with the definition of this specific header in [RFC 2183](https://www.rfc-editor.org/rfc/rfc2183.html).

This will cause certain common functions (e.g. [mime.ParseMediaType](https://pkg.go.dev/mime#ParseMediaType) in Golang) to produce an error instead of parsing out the filename successfully, thus preventing various third party downloading libraries from extracting the correct filename, leading to unexpected behavior in certain post-Comfy processing procedures.

Expected Behavior should be setting the "Content-Disposition" response header as specified in RFC 2183, which should be something like `attachment; filename=name.ext`.

### Actual Behavior

"Content-Disposition" response header set to something like `filename=name.ext`.

### Steps to Reproduce

Attempt downloading a file from "/view" URL route via various third party downloading libraries (e.g. [grab](https://github.com/cavaliergopher/grab) in Golang), resulting in saving a file named "view" locally, which normally should be correctly named like "name.ext".

### Debug Logs

```powershell
HTTP/1.1 200 OK
Content-Disposition: filename="vace14b_00003.mp4"
Content-Type: video/mp4
Etag: "18521d76691232cf-3102a6e"
Last-Modified: Mon, 14 Jul 2025 12:20:00 GMT
Content-Length: 51391086
Accept-Ranges: bytes
Date: Tue, 15 Jul 2025 03:51:51 GMT
connection: keep-alive
```

### Other

_No response_