Expose a stable error_code on chunked upload finalize so webmail can prompt wallet top-up instead of a generic upload failure. Co-authored-by: Cursor <cursoragent@cursor.com>
Scaffolded from the Ladill mini/events extraction pattern: multi-file transfers, retention controls, public landing pages, analytics, and Gitea deploy workflow. Co-authored-by: Cursor <cursoragent@cursor.com>