Recipients can be emailed the download link immediately and at optional
reminders (7/3/1 days before unavailable, or when grace period starts).
Co-authored-by: Cursor <cursoragent@cursor.com>
Files stay available while wallet renewals succeed each month. Failed renewals
keep files for TRANSFER_GRACE_PERIOD_DAYS (default 15) before automatic cleanup.
Co-authored-by: Cursor <cursoragent@cursor.com>