[Bug]: CSP Error when trying to display an attachment

[mascali33]

Description

When a mail contains an attachment that can be displayed, the CSP Policy blocks the attempt to load the blob.

Steps to Reproduce

1. Go to a mail with an attachment
2. Try to display attachment
3. Get a browser error / console error (Framing 'blob:https://bulwark./2f8...' violates the following Content Security Policy directive: "frame-src 'none'". The request has been blocked.)

Expected Behavior

The attachment should display

Actual Behavior

The browser blocks the frame containing the blob with attachment

Bulwark Version

1.4.14

Stalwart Mail Server Version

No response

Browser

Chrome / Chromium

Operating System

Linux

Screenshots / Screen Recording

No response

Relevant Logs or Error Output

Additional Context

It seems like the problem is the proxy.ts setting frame-src to none:

webmail/proxy.ts

Line 26 in 1689315

`frame-src 'none'`,

[rathlinus]

Can you try the newest beta if it is fixed?

[mascali33]

I think I'm getting CORS errors now from Stalwart... I'll try to diagnose this today when I get a bit more time :)
thanks for the commit anyways :)