Restructure step R: the app is Starsync (dev.foxyz.starsync)

- Linux app id dev.foxyz.starsync, binary starsync; Windows starsync.exe,
  company foxyz; server starsync-server; Dart package starsync; archives
  starsync-<ver>-*.
- 1.2.x compatibility: watch_together and watch-together-server
  launchers (Linux) / copies (Windows) in the archive; the updater
  accepts both names and relaunches the new binary; update.sh/.bat use
  whichever server exists.
- First start copies (never moves) the old support folder and this
  app's Hive boxes out of ~/Documents into <support>/hive; a marker
  makes it run once; AppDirs is a port; settings schema version with
  ordered migrations.
- Launcher entry dev.foxyz.starsync.desktop; the old one removed.
- Repository name and URLs unchanged.

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

apps/desktop/lib/src/state/settings.dart

@@ -6,6 +6,7 @@ import 'package:signals/signals_flutter.dart';
 
 import '../controls/model/controls_prefs.dart';
 import '../shaders/shader_presets.dart';
+import 'settings_schema.dart';
 
 // App preferences (Settings page), one Hive box. Signals start at their
 // defaults and take the stored values once [AppSettings.ensureLoaded]
@@ -134,6 +135,9 @@ class AppSettings {
   Future<void> _loadNow() async {
     try {
       final box = _box = await Hive.openBox(settingsBoxName);
+      for (final line in await migrateSettings(box)) {
+        debugPrint(line);
+      }
       final mode = box.get(_keyHwdecMode);
       hwdecMode.value = HwdecMode.values
               .where((m) => m.name == mode)