Sparkle-parity self-update for the apps/linux companion: tauri-plugin-updater +
process, checked silently on launch and from a "Check for Updates" tray item /
manual trigger. AppImage installs download, verify the signed update, and wait
for a user-confirmed restart; package-managed (deb) installs get a release-page
notice instead of replacing files the system package manager owns. The
linux-app release workflow signs the AppImage and publishes a signed latest.json
manifest that the app verifies with the committed minisign public key.
New discovery.rs browses _openclaw-gw._tcp with a lifetime mdns-sd
browser, keeps a fullname-keyed snapshot (resolved updates replace,
goodbye/TTL removes), and mirrors the native clients' TXT contract and
direct-selection gate (resolved SRV endpoint routing; tailnetDns is a
hint only). The bootstrap page lists discovered gateways and connecting
navigates the dashboard WebView to the resolved endpoint, validated
against the live snapshot; remote selection cancels the local watchdog
so an in-flight local bootstrap cannot steal the WebView back.
