New Device menu (left of Track) with "Sync Playlist to Rabbit", enabled
only when a playlist is showing and the Rabbit is plugged in. The Rabbit
mounts over MTP/gvfs (not mass storage), so device_sync.py drives it
with plain file I/O honoring the MTP caveats: no copystat, diff by
name+size. One-way mirror into Music/<Playlist>/ on the device — stale
files deleted (that folder only), Auxio-importable .m3u carries the
order, free space checked up front with a needed-vs-available alert, and
a right-justified status-bar progress bar tracks the chunked copies.
Verified live against the real Rabbit end to end.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
