Data retention and deletion

Workspace retention policies can remove old attachments, mark the attachment as deleted in chat history, and delete the encrypted backing file through the same storage path used by user-initiated deletes.

Deleted attachments keep enough context to show that an item was removed, but downloads are disabled and thumbnail data is cleared. Sender deletion and retention deletion use different deleted reasons so clients can display the correct explanation.

Administrative exports include workspace data and files and are encrypted before delivery. User wipe and full workspace wipe remove message/user data and the encrypted files associated with that data.