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

apps/desktop/test/sync_playback_e2e_test.dart

@@ -0,0 +1,93 @@
+import 'dart:async';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:media_kit/media_kit.dart';
+import 'package:sync_relay_core/core.dart';
+import 'package:sync_relay_server/server.dart';
+import 'package:watch_together/src/session/session_coordinator.dart';
+
+const _port = 18080;
+const _secret = 'e2e-secret';
+const _mediaPath = '/home/foxyz/Videos/chiyo.mp4';
+
+Future<void> _poll(
+  FutureOr<bool> Function() cond,
+  String what, {
+  Duration timeout = const Duration(seconds: 30),
+}) async {
+  final deadline = DateTime.now().add(timeout);
+  while (DateTime.now().isBefore(deadline)) {
+    if (await cond()) return;
+    await Future.delayed(const Duration(milliseconds: 200));
+  }
+  fail('timed out waiting for $what');
+}
+
+Future<void> _quiet(SessionCoordinator c) async {
+  await c.playback.player.setVolume(0);
+  try {
+    final dynamic platform = c.playback.player.platform;
+    await platform?.setProperty('loop-file', 'inf');
+  } catch (_) {}
+}
+
+void main() {
+  test(
+    'two app coordinators split play on readiness over real server',
+    timeout: const Timeout(Duration(minutes: 4)),
+    () async {
+      MediaKit.ensureInitialized();
+      final server = RoomServer(const AppConfig(
+        port: _port,
+        secret: _secret,
+        name: 'room',
+        mediaPath: _mediaPath,
+      ));
+      await server.start();
+
+      final host = SessionCoordinator();
+      final viewer = SessionCoordinator();
+      try {
+        await host.connect(const ConnectParams(
+          host: '127.0.0.1',
+          port: _port,
+          secret: _secret,
+          name: 'host',
+        ));
+        await viewer.connect(const ConnectParams(
+          host: '127.0.0.1',
+          port: _port,
+          secret: _secret,
+          name: 'viewer',
+        ));
+        await _quiet(host);
+        await _quiet(viewer);
+
+        expect(host.playback.player.state.playing, isFalse,
+            reason: 'media must open paused, not autoplay');
+        expect(viewer.playback.player.state.playing, isFalse);
+
+        await _poll(() => host.room.peek() != null, 'host room state');
+        host.toggleReady();
+        await Future.delayed(const Duration(seconds: 5));
+        expect(host.room.peek()?.transport, 'held',
+            reason: 'one Space with company present must not solo-play');
+        expect(host.playback.player.state.playing, isFalse);
+        expect(viewer.playback.player.state.playing, isFalse);
+
+        viewer.toggleReady();
+        await _poll(
+          () =>
+              host.room.peek()?.transport == 'playing' &&
+              viewer.playback.player.state.playing &&
+              host.playback.player.state.playing,
+          'both players playing once quorum readies',
+        );
+      } finally {
+        await host.dispose();
+        await viewer.dispose();
+        await server.stop();
+      }
+    },
+  );
+}