added teacher-focused lesson sheet with direct class and teacher timetable links

lib/storage/modules_settings.dart

@@ -10,12 +10,16 @@ class ModulesSettings {
   List<Modules> hiddenModules;
   bool autoFillBottomBar;
   int fixedBottomBarSlots;
+  // Set once the teacher module defaults were applied, so a module the teacher
+  // re-enables afterwards stays visible.
+  bool teacherDefaultsApplied;
 
   ModulesSettings({
     required this.moduleOrder,
     required this.hiddenModules,
     this.autoFillBottomBar = true,
     this.fixedBottomBarSlots = 3,
+    this.teacherDefaultsApplied = false,
   });
 
   factory ModulesSettings.fromJson(Map<String, dynamic> json) =>

lib/storage/modules_settings.g.dart

@@ -16,6 +16,7 @@ ModulesSettings _$ModulesSettingsFromJson(Map<String, dynamic> json) =>
           .toList(),
       autoFillBottomBar: json['autoFillBottomBar'] as bool? ?? true,
       fixedBottomBarSlots: (json['fixedBottomBarSlots'] as num?)?.toInt() ?? 3,
+      teacherDefaultsApplied: json['teacherDefaultsApplied'] as bool? ?? false,
     );
 
 Map<String, dynamic> _$ModulesSettingsToJson(
@@ -27,6 +28,7 @@ Map<String, dynamic> _$ModulesSettingsToJson(
       .toList(),
   'autoFillBottomBar': instance.autoFillBottomBar,
   'fixedBottomBarSlots': instance.fixedBottomBarSlots,
+  'teacherDefaultsApplied': instance.teacherDefaultsApplied,
 };
 
 const _$ModulesEnumMap = {