Grow lesson skills only when the assigned teacher is standing in the room.

The timetable already named a teacher; learning ignored whether they were in the toilet, still walking, or not a person at all.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/HSchool.Simulation/School.cs

@@ -17,6 +17,7 @@ public sealed class School : IDisposable
 
     private bool _disposed;
     private readonly List<PersonLogEvent> _dayLog = [];
+    private readonly HashSet<string> _lessonLogOnce = new(StringComparer.Ordinal);
 
     internal School(int id, string name, DateTime startDate, DefCatalog? catalog, MapLayout? map)
     {
@@ -135,10 +136,26 @@ public sealed class School : IDisposable
     {
         _dayLog.Clear();
         LoggedActivity.Clear();
+        _lessonLogOnce.Clear();
     }
 
     internal void AppendDayLog(PersonLogEvent row) => _dayLog.Add(row);
 
+    /// <summary>
+    /// Lesson-quality rows fire every tick the condition holds. One key per person per day is enough.
+    /// </summary>
+    internal bool TryLogLessonOnce(string personId, string type, string subject)
+    {
+        var key = string.Concat(personId, "\0", type, "\0", subject);
+        if (!_lessonLogOnce.Add(key))
+        {
+            return false;
+        }
+
+        AppendDayLog(new PersonLogEvent(personId, Clock.Time, type, subject));
+        return true;
+    }
+
     public void QueueDecision(string personId)
     {
         ObjectDisposedException.ThrowIf(_disposed, this);