S-UI-X Extended v1.0.4-hotfix1

Hotfix for the AWG device key-encryption key.

• The systemd installer now generates AWG_KEY_ENC on install and upgrade, alongside the existing SUI_SECRETBOX_KEY and SUI_COOKIE_KEY. Without it, creating a managed AmneziaWG device failed with awg: AWG encryption key is unavailable. The key is written to /etc/s-ui/secretbox.env and shown once when first generated.
• An existing key is never regenerated: rotating it after devices exist would make their stored key material undecryptable.

Note: this build is versioned 1.0.4-hotfix1. A prerelease suffix sorts below 1.0.4, so the in-panel auto-update on a 1.0.4 install will not offer it; install it explicitly by re-running the installer or updating from the tag.

If your panel already hit this error, add the key once and restart (only when no managed AWG devices exist yet):

umask 077
printf 'AWG_KEY_ENC=%s\n' "$(head -c 32 /dev/urandom | base64 | tr -d '\r\n')" >> /etc/s-ui/secretbox.env
chmod 600 /etc/s-ui/secretbox.env
systemctl restart s-ui

Full release notes: docs/releases/v1.0.4-hotfix1.md.