#790 send_email fails in IPC mode - Vault SSL cert not accessible in chroot

When apps call ctx.send_email() in IPC isolation mode, the email_tool tries to fetch SMTP credentials from Vault. But the chroot sandbox doesn't have access to /opt/venv/lib/python3.13/site-packages/certifi/cacert.pem, causing SSL verification to fail. Fix: Route send_email through IPC to parent process like other tools (http_request, shell_command, db_*).