Wire sick-teacher stay-home into cancelled lessons.

Heavy flu keeps the assigned teacher off the day plan; pupils get 48/73 no-teacher marks and a one-shot LessonCancelled notice instead of silent empty rooms.

tests/HSchool.Content.Tests/DiseaseDefTests.cs

@@ -35,6 +35,14 @@ public class DiseaseDefTests
         Assert.True(catalog.Events.ContainsKey("DiseaseOutbreak"));
         Assert.Equal(EventTriggers.DiseaseOutbreak, catalog.Events["DiseaseOutbreak"].Trigger);
         Assert.Equal("В школе распространяется болезнь", catalog.Label("ru", catalog.Events["DiseaseOutbreak"]));
+
+        Assert.True(catalog.Events.ContainsKey("LessonCancelled"));
+        Assert.Equal(EventTriggers.LessonNoTeacher, catalog.Events["LessonCancelled"].Trigger);
+        Assert.Equal(EventSeverities.Info, catalog.Events["LessonCancelled"].Severity);
+        Assert.False(catalog.Events["LessonCancelled"].Pause);
+        Assert.Equal(8000, catalog.Events["LessonCancelled"].TtlMs);
+        Assert.Equal("Урок без учителя", catalog.Label("ru", catalog.Events["LessonCancelled"]));
+        Assert.Equal("Lesson without a teacher", catalog.Label("en", catalog.Events["LessonCancelled"]));
     }
 
     [Fact]

tests/HSchool.Content.Tests/EventDefTests.cs

@@ -42,6 +42,10 @@ public class EventDefTests
         Assert.Equal(EventActions.None, catalog.Events["DirectorSummoned"].Action);
         Assert.Equal("Ученика вызвали к директору", catalog.Label("ru", catalog.Events["DirectorSummoned"]));
         Assert.Equal("A pupil was summoned to the principal", catalog.Label("en", catalog.Events["DirectorSummoned"]));
+
+        Assert.True(catalog.Events.ContainsKey("LessonCancelled"));
+        Assert.Equal(EventTriggers.LessonNoTeacher, catalog.Events["LessonCancelled"].Trigger);
+        Assert.Equal("Урок без учителя", catalog.Label("ru", catalog.Events["LessonCancelled"]));
     }
 
     [Fact]