WiFi screen: reach the root helper through a socket instead of sudo; adapter dropdown

The kiosk app can end up with the no-new-privileges flag, after which sudo
refuses to run ("The no new privileges flag is set"). The helper is now
served over a root-owned, kiosk-group-only unix socket (systemd socket
activation); sudo stays as a fallback. With several WiFi adapters the screen
shows a dropdown and lists all of them; status/scan/connect take an iface.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013wi3ZQveYdjfcrEsyazq32

menus/complete_uninstall.sh

@@ -110,6 +110,8 @@ action_complete_uninstall() {
     sudo rm -rf "$KIOSK_HOME"
 
     echo "[6/12] Removing remaining systemd units..."
+    sudo systemctl disable --now kiosk-wifi-helper.socket 2>/dev/null || true
+    sudo rm -f "$SYSTEMD_DIR"/kiosk-*.socket
     sudo rm -f "$SYSTEMD_DIR"/kiosk-*.service
     sudo rm -f "$SYSTEMD_DIR"/kiosk-*.timer
     sudo systemctl daemon-reload 2>/dev/null || true