Add DM leaks metadata warning

[alltheseas]

design

How might we share with user that DMs leak metadata by nostr design?

Should Damus remind user at the start of every new conversation?

Should Damus also suggest that deletion may not be possible?

@robagreda

[alltheseas]

Recently it was revealed non text attachments (e.g. media, images) are stored without encryption on signal desktop. This came as a surprise to signal users. signalapp/Signal-Desktop#5751

Damus NIP-04 DMs should inform user of non-private metadata, and reduce negative suprises.

[jb55]

Recently it was revealed non text attachments (e.g. media, images) are stored without encryption on signal desktop. This came as a surprise to signal users

damus doesn't store anything unencrypted at rest, and we're in an OS sandbox, so this issue doesn't really apply to us. but yes public DM metadata is a problem.

This should be solved once we switch to something like giftwraps:

• Explore DM gift wrap #1737
• First-class giftwrap support nostrdb#31