v0.1.30-pre.70 preview: a send that failed and will not go now says what it is still holding. The details behind a red message name the file and what it weighs, beside the Discard that removes both, and Settings > Storage lists "Attachments waiting to send" as a group of its own with a row per chat that opens it. The Storage note no longer claims attachments are never kept in the database - a sent one is not, one still waiting is. Nothing is deleted by itself and no schema change.