Opening Connections called find_device() on the GUI thread, which lists the
gvfs-MTP mount; on a wedged mount that blocks forever in an uninterruptible
FUSE wait and the app had to be force-quit. DeviceWatcher now probes on a
daemon thread (one at a time, STUCK after 3 s, late answers still land), the
menu reads its cached answer, and a stuck mount shows "Rabbit isn't
responding…" with a Reset Connection button (kill gvfsd-mtp, remount via
gio). Tests can no longer reach the real mount (conftest patches
find_device), which also takes the suite from ~200 s to ~22 s.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
