Approval emails for access requests now reliably tracked

Admins can see delivery status and re-send approval emails from the access-request sheet.

Bug Fixes

Access-request approval emails are now routed through the EmailOutbox pipeline, matching how buyer notification emails are handled. Previously they called the mailer directly, causing Resend webhooks to fail with 500 errors when trying to update tracking records that didn't exist.

Admins now see approval email delivery status on the access-request sheet — including the status badge (Sending, Sent, Delivered, Failed), delivery timestamp, attempt count, and error details. When an approval email fails, admins can re-send it directly from the sheet without manual intervention.