Corral v0.6.1 — desktop installers actually install

Fixes the desktop installers. The packaged app's backend was missing several modules (push.js, webpush.js, remote.js, connectproxy.js), so on Windows/macOS/Linux the app started, sat in the tray, and never opened its window — the bundled backend crashed before it could listen. The installer now ships the complete backend.

If v0.6.0 (or an earlier desktop build) only ever gave you a tray icon: install this one over it and launch again. Nothing else changed — the phone app and multi-ranch features are identical to v0.6.0.

Unsigned builds — macOS: right-click the app and choose Open the first time. Windows: SmartScreen → More info → Run anyway. Android: install the APK (allow unknown sources), then pair via the QR in the desktop titlebar.