pauseAllFor method
Pauses all active foreground sessions owned by appId.
Implementation
Future<void> pauseAllFor(String appId) async {
final prefix = '$appId\u0000';
final sessions = _sessions.entries
.where((entry) => entry.key.startsWith(prefix))
.map((entry) => entry.value)
.toList(growable: false);
for (final session in sessions) {
await session.pause();
}
}