Add a full-node daemon updater (util/DaemonUpdater + daemon_download_dialog)
reachable from Settings -> NODE & SECURITY: downloads/verifies (SHA-256 +
enforced ed25519 signature) and atomically installs the latest dragonxd from
the project Gitea, with a "Restart daemon now" step. Add a shared "Browse all
releases..." picker (release_list_view) to both the miner and daemon updaters
so users can pin older/pre-release builds. Pure no-I/O cores
(daemon_updater_core / xmrig_updater_core) are unit-tested; sign-daemon-release.sh
signs release archives offline.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
