Protocol 11: sit out replaces kicking; nudge

Anyone can sit anyone out (host included); only you bring yourself back.
Out members stay in chat and the party, never block or count, and load no
media; a card with the live position and Join back (Space) replaces the
video. The mini player's x sits you out; optionally idle does too. Nudge:
the server forwards it to the target only (3/s, 20/min per sender); the
target hears the nudge sound, gets a toast and a taskbar attention
request. Kick, its messages, errors and dialog are gone.

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

apps/desktop/lib/src/screens/home/connect_flow.dart

@@ -23,10 +23,6 @@ class ConnectFlow extends ChangeNotifier {
   int _attempt = 0;
   bool _disposed = false;
 
-  /// Set when an attempt ends in a kick, so the shell shows the removal
-  /// dialog.
-  void Function(String reason)? onKicked;
-
   @override
   void dispose() {
     _disposed = true;
@@ -110,12 +106,7 @@ class ConnectFlow extends ChangeNotifier {
     } catch (e) {
       if (myAttempt != _attempt) return;
       busy = null;
-      final kick = _session.coordinator.kickReason.peek();
-      if (kick != null && kick.isNotEmpty) {
-        onKicked?.call(kick);
-      } else {
-        errors[mode] = CardError('Could not connect', '$e');
-      }
+      errors[mode] = CardError('Could not connect', '$e');
       _notify();
       return;
     }