Initial commit: watch-together phases 0-4 + presence hardening, internet-tested

apps/desktop/lib/src/sfx/sfx.dart

@@ -0,0 +1,72 @@
+enum SfxKind {
+  ready,
+  unready,
+  forceReady,
+  forceUnready,
+  forcePlay,
+  forceHold,
+  kick,
+  join,
+  leave,
+  stale,
+  swap,
+  seek,
+  pause,
+  resume,
+  chat,
+  warn,
+}
+
+class SfxCue {
+  final SfxKind kind;
+  final int readyIndex;
+  const SfxCue(this.kind, {this.readyIndex = 0});
+}
+
+SfxKind? sfxForFeedAction(String action) {
+  switch (action) {
+    case 'ready':
+      return SfxKind.ready;
+    case 'unready':
+      return SfxKind.unready;
+    case 'force-ready':
+      return SfxKind.forceReady;
+    case 'force-unready':
+      return SfxKind.forceUnready;
+    case 'force-play':
+      return SfxKind.forcePlay;
+    case 'force-hold':
+      return SfxKind.forceHold;
+    case 'kick':
+      return SfxKind.kick;
+    case 'join':
+      return SfxKind.join;
+    case 'leave':
+      return SfxKind.leave;
+    case 'stale':
+      return SfxKind.stale;
+    case 'swap':
+      return SfxKind.swap;
+    case 'seek':
+      return SfxKind.seek;
+    case 'pause':
+      return SfxKind.pause;
+    case 'resume':
+      return SfxKind.resume;
+    case 'chat':
+      return SfxKind.chat;
+    default:
+      return null;
+  }
+}
+
+abstract class SfxService {
+  Future<void> play(SfxCue cue);
+}
+
+class NoopSfxService implements SfxService {
+  const NoopSfxService();
+
+  @override
+  Future<void> play(SfxCue cue) async {}
+}