Mark still-running tests as crashed when run completes

When NUnit sends RunCompletedEvent, any tests that were started but
never received a completion event are marked as crashed. This prevents
the runner from hanging indefinitely waiting for results that will
never come.

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: rogeralsing

src/Asynkron.TestRunner/TestRunner.cs

@@ -158,6 +158,14 @@ await AnsiConsole.Live(display.Render())
                                     break;
 
                                 case RunCompletedEvent:
+                                    // Mark any still-running tests as crashed (they never completed)
+                                    foreach (var fqn in running.ToList())
+                                    {
+                                        running.Remove(fqn);
+                                        pending.Remove(fqn);
+                                        results.Crashed.Add(fqn);
+                                        display.TestCrashed(fqn);
+                                    }
                                     break;
 
                                 case ErrorEvent:
@@ -267,6 +275,16 @@ private async Task RunWithRecoveryQuietAsync(string assemblyPath, List<string> a
                             break;
 
                         case RunCompletedEvent:
+                            // Mark any still-running tests as crashed
+                            foreach (var fqn in running.ToList())
+                            {
+                                running.Remove(fqn);
+                                pending.Remove(fqn);
+                                results.Crashed.Add(fqn);
+                                AnsiConsole.MarkupLine($"[red]  💥[/] {fqn} [red](NO RESULT)[/]");
+                            }
+                            break;
+
                         case ErrorEvent:
                             break;
                     }