The stub dbus_property() returned a bare function, so the read/write
properties (@Volume.setter and friends) raised AttributeError at import
time. That made any host without dbus-next -- macOS, Windows, minimal
containers -- crash before the TUI could start, because app.py imports
this module unconditionally.
Replace the stub with a descriptor that supports .getter()/.setter(), and
give the service a short label for the status bar.
beefcarver