v0.32.0: folder tree in Rabbit Sync Settings, quieter art pass, tink, VLC-style Preferences

- Rabbit Sync Settings shows the sidebar's folder tree. A folder has its own
  tristate checkbox; a fully ticked folder is stored as device_sync.folder_ids
  and follows the folder, so playlists added to it later sync too.
- The album-art pass compares covers against the sizes the planner's device
  scan already read (plan.art_sizes) instead of an MTP stat per album, caches
  "no art" as a .none marker, and only unlinks covers that are really there.
  The summary reports covers actually updated rather than every cover.
- A quiet tink when a Rabbit sync, export or URL import finishes, with an
  on/off switch (sound_effects, on by default).
- Preferences is now General / Appearance / Integrations, a list on the left
  and the page on the right, opened big enough for the tallest page.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

setup.py

@@ -17,6 +17,7 @@ setup(
     # The andTunes APK LinTunes installs, and the default button artwork
     # sync ships to the device.
     package_data={
+        "lintunes": ["sounds/*.wav"],
         "lintunes.export": ["templates/*"],
         "lintunes.android": ["andTunes.apk", "andTunes.json"],
         "lintunes.andtunes": ["buttons/*.png"],