show classname instead of teacher name in teacher timetable view

ios/TimetableWidgetExtension/WidgetData.swift

@@ -27,6 +27,8 @@ struct WidgetLesson: Codable {
     let subjectShort: String
     let subjectLong: String?
     let room: String?
+    // On teacher accounts this carries the class label ("7a") instead of the
+    // teacher short name (originalTeacher is nil then) — mapped in Dart.
     let teacher: String?
     let originalTeacher: String?
     let status: WidgetLessonStatus