Keep messages permanently, solution idea

I really like this idea, especially for self-hosting. I think tying it to a dedicated role permission is important, otherwise users could simply mark everything as permanent and effectively bypass Media Expiry. One thing I'd especially like to see is the ability to mark an existing attachment as permanent after it has already been uploaded, e.g. via the attachment/message context menu: Keep permanently → exempts the attachment from Media Expiry Use normal expiry → puts it back under the instance's normal expiry rules A dedicated permission such as “Manage permanent media” / “Exempt attachments from expiry” would make sense to me, so this could be given to moderators without necessarily tying it to “Manage Messages”. Ideally this could also respect channel permission overrides, so for example moderators could preserve files in a resources/rules channel without having that ability everywhere. It might also be useful for these actions to appear in the audit log. “Permanent” should only mean exempt from automatic Media Expiry — deleting the actual message should still delete the attachment normally.