feat(machine): landscape layout and fullscreen mode

- Switch Electron window to landscape (1920x1080) with fullscreen fallback
- Rearrange IdleView for horizontal layout (logo+badges left, action cards right)
- Fix hostname command in provision/build scripts (use ip route instead of hostname -I)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

deploy/nixos/provision-atm.sh

@@ -56,7 +56,7 @@ if [ "$ATM_HOST" = "localhost" ]; then
     echo ""
     echo "--- QEMU detected: using $HOST_IP as host gateway ---"
 else
-    HOST_IP=$(hostname -I | awk '{print $1}')
+    HOST_IP=$(ip -4 route get 1 | awk '{print $7; exit}')
     echo ""
     echo "--- LAN ATM: using $HOST_IP as dev machine address ---"
 fi